Chair News

Electronic and Quantum Properties of Organic Two-Dimensional Crystals

November 8, 2024

Summary: In a paper published in Nature Reviews Materials, scientists at the Max Planck Institute of Microstructure Physics and TUD share insights on exploring organic 2D crystals for electronic and quantum communities, aiming to bridge ideas from chemistry, materials science, and physics to inspire innovative concepts for future research.

Organic 2D crystals (O2DCs) are an emerging class of synthetic layered materials, composed of π-conjugated building blocks, that display extended π-conjugation in the 2D plane and/or interlayer electronic couplings. The π-conjugated building blocks are connected in-plane by strong linkages, typically covalent or coordination bonds, and layers are held together by non-covalent interactions. The out-of-plane couplings between layers, driven by π–π stacking interactions, influence the stability and electronic properties of the materials, a phenomenon termed the ‘proximity effect’. Like inorganic 2D crystals, O2DCs can be synthesized by exfoliation or directly on surfaces or at interfaces, yielding monolayer or few-layer nanosheets. Their modular nature and layer-dependent properties allow their structures and properties to be customized extensively at the molecular level. Advances in engineering the structural topology, building blocks and linkage chemistry of O2DCs, as well as in understanding their structure-property relationships, have aided the discovery of new materials that behave as insulators, semiconductors, semimetals or metals, with direct and indirect ranging from ultraviolet via the visible range and infrared into the radio frequencies region. In addition, theoretical and experimental studies have demonstrated the presence of unique quantum states in O2DCs. These characteristics position O2DCs as a a versatile toolkit for exploring fascinating electronic and quantum phenomena that are crucial for potential applications in electronics, optoelectronics, spintronics, quantum computing and quantum sensing.

A recent review by researchers from the Max Planck Institute of Microstructure Physics and TUD, published in Nature Reviews Materials, delves into the advances, challenges, and opportunities in this rapidly evolving field. In particular, the authors discussed the structure-property relationships and synthetic strategies of O2DCs, with particular emphasis on their unique electronic structures, charge transport properties and the emergence of quantum states, such as topological and superconducting phases, alongside different spin states. Furthermore, emerging device applications of O2DCs across electronics, optoelectronics and spintronics are highlighted, followed by a critical overview of future research and the persistent challenges in synthetic chemistry, physics and materials science that must be addressed to further advance this field. This work provides a foundational roadmap for developing O2DCs and their integration into advanced electronic, optoelectronic, and quantum technologies.

Acknowledgements: This work was financially supported by an ERC Consolidator Grant (T2DCP, no. 819698) and DFG projects (2D polyanilines, no. 426572620; GRK2861, no. 491865171; and CRC 1415, Chemistry of Synthetic Two-Dimensional Materials, no. 417590517). The authors thank P. L. Koko and R. Zhao for providing the energy levels in Fig. 1b,f.

Reference: Zhiyong Wang, Mingchao Wang, Thomas Heine, and Xinliang Feng. Electronic and quantum properties of organic two-dimensional crystals. Nat. Rev. Mater. (2024). https://doi.org/10.1038/s41578-024-00740-8

Research project 2DPolyMembrane receives 10 Million Euro

November 5, 2024

Scientists from the Max Planck Institute of Microstructure Physics in Halle receive the prestigious Synergy Grant of the European Research Council to work jointly on 2DPolymembrane.

The European Research Council (ERC) has awarded a prestigious €10 million Synergy Grant to 2DPolymembrane, a research project aiming to develop ultra-thin, high-precision two-dimensional polymer membranes with transformative applications in energy and environmental science.

Prof. Xinliang Feng, Director at the Max Planck Institute of Microstructure Physics in Halle, acts as the corresponding Principal Investigator in this new research project, which unites research teams from the Technical University of Dresden and Leiden University in the Netherlands. “2DPolyMembrane” will be funded by the EU for six years, beginning in April 2025.

“This ERC Synergy Grant is a tremendous recognition of the collaborative work we’re doing to push the boundaries of 2D polymer membrane-based technologies. Our approach opens the door to breakthrough applications in energy storage and power generation. This research will push the boundaries of what’s possible, offering solutions that can lead to significant advancements in sustainability and performance across multiple sectors.”, said Feng looking into the future.

Xinliang Feng (MPI Halle), Grégory Schneider (Leiden University), and Thomas Heine (Technical University of Dresden) © MPI of Microstructure Physics

All team members from the Max Planck Institute in Halle, Technical University of Dresden, and Leiden University, Netherlands have profound expertise in the area of 2D polymer materials in physical chemistry and complement each other in this research project. Xinliang Feng will establish the novel synthesis of 2D polymer-based heterostructure membranes (2DHMs) with new design and synthetic strategies, and demonstrate the innovative integration of 2DHM membranes in aqueous battery devices. Thomas Heine, Principal Investigator from the Technical University of Dresden, will provide a detailed understanding of ion transport via a wide range of methods to enable the rational design of 2DHMs. Grégory Schneider from Leiden University, Netherlands, brings the surface chemistry component to tune ion flow and understand the ion transport phenomenon, as well as provide expertise across different aspects of the collaborative approach to maximize the success of this project.

2DPolymembrane will unlock the unique opportunities of 2DHMs for ion transport phenomenon and develop innovative energy device integrations (proton/aqueous metal batteries, fuel cells, and reverse osmotic power generators), where the merits of ultrathin precision 2DHMs will result in the highest selectivity and highest particle flow, and thus a fundamental device performance beyond the state-of-art. This project will achieve innovative 2DHMs for selective proton and ion transport with high permeance, laying the foundations for next-generation membrane technologies.

The majority of the grant will finance postdoctoral research fellows and Ph.D. students to collaborate at the participating institutions.

About the Synergy Grant

In the case of the ERC Synergy Grants, research projects are funded specifically for projects carried out by a group of two to four individual Principal Investigators (PIs) working together and bringing different skills and resources to tackle ambitious research problems. Synergy Grants can be up to a maximum of € 10 million for a period of 6 years. The grant scheme is designed to support ambitious research projects that require the collaborative efforts of two to four academic research groups. Grants are awarded based on the scientific excellence of the proposal and the anticipated intrinsic benefits of interdisciplinary synergy.

About the ERC

The ERC, set up by the European Union in 2007, is the premier European funding organization for excellent frontier research. It funds creative researchers of any nationality and age, to run projects based across Europe. The ERC offers four core grant schemes: Starting Grants, Consolidator Grants, Advanced Grants, and Synergy Grants. With its additional Proof of Concept Grant scheme, the ERC helps grantees to bridge the gap between their pioneering research and early phases of its commercialization. The ERC is led by an independent governing body, the Scientific Council. Maria Leptin has been the President of the ERC since November 2021. The overall ERC budget from 2021 to 2027 is more than €16 billion, as part of the Horizon Europe programme, under the responsibility of European Commissioner for Innovation, Research, Culture, Education and Youth, Iliana Ivanova.

Source: https://www.mpi-halle.mpg.de/research-project-2dpolymembrane-receives-10-million-euro?c=178485

Fundamental quantum model recreated from nanographenes

October 31, 2024

One step closer to quantum technologies

Quantum technologies exploit the unusual properties of the most fundamental building blocks of matter. They promise breakthroughs in communication, computing, sensors and much more. However, quantum states are fragile, and their effects are difficult to grasp, making research into real-world applications challenging. Empa researchers and their partners have now achieved a breakthrough: Using a kind of “quantum Lego”, they have been able to accurately realize a well-known theoretical quantum physics model in a synthetic material.

With utmost precision: Using special nanographene molecules, the researchers were able to realize a theoretical model from quantum physics. Image: Empa

The smallest unit of information in a computer is the bit: on or off, 1 or 0. Today, the world's entire computing power is built on the combination and interconnection of countless ones and zeros. Quantum computers have their own version of the bit: the qubit. It, too, has two basic states. The main difference: Quantum effects allow a superposition of the two states, so that the qubit is not either 1 or 0, but both at the same time. With different proportions of 0 and 1, the qubit can theoretically assume an infinite number of states.

This ambiguity should give quantum computers true “superpowers”. At least in theory, quantum-based computers can perform calculations in fractions of a second that stump today's best supercomputers. However, quantum computing is not yet fully developed. One of the biggest challenges is linking the qubits – since one single (qu)bit is not much of a computer.

One way to realize the 0 and the 1 of the qubit is via the alignment of the so-called electron spin. The spin is a fundamental quantum mechanical property of electrons and other particles, a kind of torque that, put simply, can point “up” (1) or “down” (0). When two or more spins are quantum-mechanically linked, they influence each other's states: Change the orientation of one, and it will also change for all the others. This is therefore a good way to make qubits “talk” to each other. However, like so much in quantum physics, this “language”, i.e. the interaction between the spins, is enormously complex. Although it can be described mathematically, the relevant equations can hardly be solved exactly even for relatively simple chains of a just few spins. Not exactly the best conditions for putting theory into practice...

A model becomes reality

Researchers at Empa's nanotech@surfaces laboratory have now developed a method that allows many spins to “talk” to each other in a controlled manner – and that also enables the researchers to “listen” to them, i.e. to understand their interactions. Together with scientists from the International Iberian Nanotechnology Laboratory and the Technical University of Dresden, they were able to precisely create an archetypal chain of electron spins and measure its properties in detail. Their results have now been published in the renowned journal Nature Nanotechnology.

The theory behind the chain is familiar to all physics students: Take a linear chain of spins in which each spin interacts strongly with one of its neighbors and weakly with the other. This so-called one-dimensional alternating Heisenberg model was described almost 100 years ago by physicist and later Nobel Prize laureate Werner Heisenberg, one of the founders of quantum mechanics. Although there are materials in nature that contain such spin chains, it has not yet been possible to deliberately incorporate the chains into a material. “Real materials are always much more complex than a theoretical model,” explains Roman Fasel, head of Empa's nanotech@surfaces laboratory and co-author of the study.

A “goblet” made of carbon

To create such an artificial quantum material, the Empa researchers used tiny pieces of the two-dimensional carbon material graphene. The shape of these nanographene molecules influences their physical properties, in particular their spin – a kind of nano-sized quantum Lego brick from which the scientists can assemble longer chains.

For their Heisenberg model, the researchers used the so-called Clar's Goblet molecule. This special nanographene molecule consists of eleven carbon rings arranged in an hourglass-like shape. Due to this shape, there is an unpaired electron at each end – each with an associated spin. Although predicted by chemist Erich Clar as early as 1972, Clar's Goblet was only produced in 2019 by Fasel's team at the nanotech@surfaces laboratory.

Left: High-resolution scanning tunneling microscopy image of Clar's Goblet. Right: Structural model of Clar's Goblet (blue: spin up, red: spin down). Image: Empa

The researchers have now linked the goblets on a gold surface to form chains. The two spins within a molecule are weakly linked, while the spins from molecule to molecule are strongly linked – a perfect realization of the alternating Heisenberg chain. The researchers were able to precisely manipulate the length of the chains, selectively switch individual spins on and off and “flip” them from one state to another, allowing them to investigate the complex physics of this novel quantum material in great detail.

From theory to practice

Fasel is convinced that, just as the synthesis of Clar's Goblet enabled the production of Heisenberg chains, this study will in turn open new doors in quantum research. “We have shown that theoretical models of quantum physics can be realized with nanographenes in order to test their predictions experimentally,” says the researcher. “Nanographenes with other spin configurations can be linked to form other types of chains or even more complex systems.” The Empa researchers are leading by example: In a second study, which is about to be published, they were able to recreate a different type of Heisenberg chain in which all spins are equally linked.

A scanning tunneling microscopy image shows the spin chain made of individual Clar's Goblets. Image: Empa

To be at the forefront of applied quantum physics, theoretical and experimental scientists from different disciplines need to work together. Chemists at Dresden University of Technology provided Empa researchers with the starting molecules for their synthesis of Clar's Goblets. And researchers from the International Iberian Nanotechnology Laboratory in Portugal contributed their theoretical expertise to the project. The theory needed for such breakthroughs is not (just) what you find in physics textbooks, Fasel emphasizes, but a sophisticated transfer between the quantum physics model and the experimental measurements.

Credit: Empa

Successful PhD defence of Dongqi Li

October 29, 2024

Dongqi Li successfully defended his PhD thesis on "Controllable Synthesis of MXenes with Novel and Ordered Terminations" on October 22, 2024. Congratulations to Dongqi Li!

Dr. Wenhui Niu Receives the Arthur K. Doolittle Award from the American Chemical Society 2024 Fall Meeting

September 6, 2024

Dr. Wenhui Niu receives the 2024 Fall Arthur K. Doolittle Award from the ACS Division of Polymeric Materials: Science and Engineering (PMSE), for the talk entitled “Topological Engineering of Graphene Nanoribbon for Next Generation Electronics”.

The Arthur K. Doolittle Award recognizes an outstanding talk presented during a PMSE symposium at each of the Fall and Spring ACS National Meetings. All oral PMSE presentations are eligible for nomination by symposium organizers on the basis of content with emphasis on originality, impact, and development of new concepts in polymeric materials. Recipients are selected by an anonymous panel of judges appointed by the PMSE Doolittle Award Committee.

About Dr. Wenhui Niu

Wenhui Niu was born in China in 1994. She obtained her B.Sc. in polymer engineering from Sichuan University in 2016 and her Ph.D. in chemistry under the supervision of Prof. Yiyong Mai at Shanghai Jiao Tong University in 2021. During her Ph.D. work, she pioneered the topological engineering of graphene nanoribbons with tailoring optoelectronics properties and excellent liquid-phase processability. After completing her PhD, Wenhui joined the Technische Universität Dresden as a postdoctoral fellow for one year, working with Prof. Xinliang Feng. After that, she joined the Max Planck Institute of Microstructure Physics as a research group leader, where her research focused on the development of novel chiral nanographenes with exceptional chiroptical properties. In 2023, Wenhui Niu was selected as a Minerva Fast Track group leader at the Max Planck Institute of Microstructure Physics, and since April 2024, she has been leading the “Quantum Chiral Nanocarbons” group. Her current research interests lie heavily on the recognition of spin polarization behavior of chiral nanocarbons and their potential applications in chiral spintronics.

About the Arthur K. Doolittle Award

The Arthur K. Doolittle Award originally established by the Union Carbide Corporation as the Carbide Award, its name was later changed due to Arthur K. Dootlittle's contribution to the ACS Division of PMSE, the field of polymeric materials, and financial contributions from royalties of his book, Technology of Solvents and Plasticizers. As the recipient of the Arthur K. Doolittle Award, the winner will receive a prize of $1,000 and a plaque, which will be presented at the PMSE/POLY Plenary Lecture and Awards Reception tentatively scheduled for Wednesday evening of the Spring 2025 National Meeting in San Diego, California.

To learn more about the Award, visit the PMSE website (https://pmsedivision.org/doolittle-award/).

Congratulations to Sebastian Obermann for successfully defending his PhD

July 16, 2024

Sebastian Obermann successfully defended his PhD thesis on "Bottom-Up Synthesis and Characterization of Non-Planar Graphene Nanoribbons" on July 11, 2024. Congratulations Dr. Obermann!

Congratulations to Kamil Jastrzembski for successfully defending his PhD

June 21, 2024

Kamil Jastrzembski successfully defended his PhD thesis on "Two-Dimensional Conjugated Metal-Organic-Frameworks based on Contorted-Hexabenzocoronene" on June 3, 2024. Congratulations Dr. Jastrzembski!

Novel Triatomic-Layer Borate Polyanion Terminations for MXenes

June 7, 2024

Two-dimensional (2D) transition metal carbides/nitrides, known as MXenes, have captured intensive attention owing to their promising applications in the areas of energy storage, (opto)electronics, environmental and future quantum technologies. Unlike other 2D materials, MXenes typically possess a layer of terminal groups capping the exposed surface metal atoms, which substantially influence the properties of MXenes. However, the terminations for hitherto developed MXenes are limited to monolayers or simple groups, showing disordered arrangements and inferior stability. The full potential of termination engineering in MXenes still calls for further investigation and exploration. Researchers from the group of Prof. Xinliang Feng and Dr. Minghao Yu, together with collaborators, show the synthesis of MXenes (Nb₂C and Ti₃C₂) with ordered triatomic-layer borate polyanion terminations through a flux-assisted eutectic molten etching approach. Lewis acidic salts in the eutectic molten state act as the etching agent to obtain the MXene backbone. Meanwhile, borax, as the flux, undergoes thermal decomposition to generate anionic BO₂⁻ species, which cap the MXene surface with an O-B-O configuration (denoted OBO-terminations). Contrasting with conventional Cl/O-terminated Nb₂C with strongly localized charge transport, OBO-terminated Nb₂C features band transport properties described by the Drude model. This transition in the conduction mechanism is attributed to the surface structure ordering enabled by OBO-terminations, which effectively mitigates charge carrier backscattering and trapping. Consequently, it results in a notable 15-fold enhancement in electrical conductivity and a tenfold improvement in charge mobility at the dc limit. Furthermore, triatomic-layer OBO-terminations provide substantially enriched Li⁺-hosting sites, enabling a high charge storage capacity for Ti₃C₂ MXenes (420 mAh g⁻¹), nearly double that of the Cl/O-terminated Ti₃C₂ (212 mAh g⁻¹). This work not only illustrate the potential for intricate termination configurations in MXenes, but also provide inspiration for further advancements in their potential applications like (opto)electronics and energy storage.

Reference: Dongqi Li, Wenhao Zheng, Sai Manoj Gali, Kamil Sobczak, Michal Horák, Josef Polčák, Nikolaj Lopatik, Zichao Li, Jiaxu Zhang, Davood Sabaghi, Shengqiang Zhou, Paweł P. Michałowski, Ehrenfried Zschech, Eike Brunner, Mikołaj Donten, Tomáš Šikola, Mischa Bonn, Hai I. Wang^*, David Beljonne^*, Minghao Yu^*. Xinliang Feng^*, MXenes with ordered triatomic-layer borate polyanion terminations, Nat. Mater. (2024). DOI: 10.1038/s41563-024-01911-2.

Acknowledgements: This work was financially supported by European Union’s Horizon 2020 research and innovation programme (GrapheneCore3 881603, LIGHT-CAP 101017821, GREENCAP 101091572), M-ERA.NET and Sächsisches Staatsministerium für Wissenschaft und Kunst (HYSUCAP 100478697), and German Research Foundation (DFG) within the Cluster of Excellence, CRC 1415 (Grant No. 417590517). TAČR EPSILON project (Nr. TH71020004), GAČR project (Nr. 23-07617S) and CzechNanoLab project (LM2023051) funded by MEYS CR are gratefully acknowledged for the financial support of the measurements in CEITEC Nano Research Infrastructure. The computational resources in Mons were supported by the FNRS “Consortium des Equipements de Calcul Intensif−CECI” program (Grant No. 2.5020.11) and by the Walloon Region (ZENOBE Tier-1 supercomputer, 1117545). D.L. was funded by China Scholarships Council (CSC). P.P.M. was supported by the National Science Centre (Project No. 2018/31/D/ST5/00399) and National Centre for Research and Development (Project No. LIDER/8/0055/L-12/20/NCBR/2021). The authors acknowledge the use of the facilities in the Dresden Center for Nanoanalysis (DCN) at Technische Universität Dresden, the GWK support for providing computing time through the Center for Information Services and High-Performance Computing (ZIH) at TU Dresden, and beam time allocation at beamline P65 at the PETRA III synchrotron (DESY, Hamburg, Germany) and beamline BL04 at ALBA synchrotron (Barcelona, Spain).

2nd Funding Phase CRC 1415 "Chemistry of Synthetic 2D Materials"

May 31, 2024

Exciting news! On Friday, 31 May 2024, Deutsche Forschungsgemeinschaft (DFG) officially announced the continuation of the interdisciplinary research project “Chemistry of Synthetic 2D Materials”. Starting 1st July 2024, the CRC 1415 will pursue its research activities in the areas of synthesis, characterization and theoretical modeling of novel 2D materials. Based on the substantial progress made during the last 4 years, the CRC will shift its scientific focus towards understanding and tailoring the functional properties of synthetic 2DMs (e.g., (opto)electronic properties, topological and magnetic properties, catalysis, as well as ion transport and ion storage properties) and will address how these properties evolve in 2D heterostructures.

We deeply thank everyone for making the interdisciplinary research program possible!

Further news:  Technische Universität Dresden, School of Science

Congratulations to Davood Sabaghi for successfully defending his PhD

April 4, 2024

Davood Sabaghi successfully defended his PhD on "High Energy and Power Density Dual-ion Batteries with Graphite as Cathode: Key Challenges and Strategies" on March 28, 2024. Congratulations Dr. Sabaghi!

Unlocking Four-Electron Conversion in Tellurium Cathodes for Advanced Magnesium-Based Dual-Ion Batteries

April 2, 2024

Magnesium (Mg) batteries hold promise as a large-scale energy storage solution, but their progress has been hindered by the lack of high-performance cathodes. Here, we address this challenge by unlocking the reversible four-electron Te₀/Te₄₊ conversion in elemental Te, enabling the demonstration of superior Mg//Te dual-ion batteries. Specifically, the classic magnesium aluminum chloride complex (MACC) electrolyte is tailored by introducing Mg bis(trifluoromethanesulfonyl)imide (Mg(TFSI)²), which initiates the Te₀/Te₄₊ conversion with two distinct charge-storage steps. Te cathode undergoes Te/TeCl⁴ conversion involving Cl_– as charge carriers, during which a tellurium subchloride phase is presented as an intermediate. Significantly, the Te cathode achieves a high specific capacity of 543 mAh g^Te_–1 and an outstanding energy density of 850 Wh kg^Te_–1, outperforming most of the previously reported cathodes. Our electrolyte analysis indicates that the addition of Mg(TFSI)² reduces the overall ion-molecule interaction and mitigates the strength of ion-solvent aggregation within the MACC electrolyte, which implies the facilized Cl_– dissociation from the electrolyte. Besides, Mg(TFSI)² is verified as an essential buffer to mitigate the corrosion and passivation of Mg anodes caused by the consumption of the electrolyte MgCl² in Mg//Te dual-ion cells. These findings provide crucial insights into the development of advanced Mg-based dual-ion batteries.

Reference: Ahiud Morag, Xingyuan Chu, Maciej Marczewski, Jonas Kunigkeit, Christof Neumann, Davood Sabaghi, Grażyna Zofia Żukowska, Jingwei Du, Xiaodong Li, Andrey Turchanin, Eike Brunner, Xinliang Feng,* Minghao Yu* Angew. Chem. Int. Ed. 2024, e202401818

Acknowledgements: This work was financially supported by European Union’s Horizon Europe research and innovation programme (ERC Starting Grant, BattSkin, 101116722), European Union’s Horizon 2020 research and innovation programme (LIGHT-CAP 101017821), German Research Foundation (DFG) within the Cluster of Excellence, CRC 1415 (Grant No. 417590517), and the European Fonds for Regional Development (Europäischer Fonds für Regionale Entwicklung; EFRE-OP 2014-2020; Project No. 2021 FGI 0035, NanoLabXPS) as part of the REACT-EU program. The authors also acknowledge the use of the facilities in the Dresden Center for Nanoanalysis (DCN) at Technische Universität Dresden, the GWK support for providing computing time through the Center for Information Services and High-Performance Computing (ZIH) at TU Dresden. We acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Parts of this research were carried out at PETRA III, and we would like to thank Edmund Welter and Dr. Andre L. C Conceição for assistance in using beamlines P65 and P62, respectively. WAXS experiments were also performed at BL11 beamline at ALBA Synchrotron with the collaboration of Dr. Cristián Huck Iriart. We acknowledge the European Synchrotron Radiation Facility (ESRF) for the provision of synchrotron radiation facilities, and we would like to thank Dr. Cesare Atzorifor's assistance and support in using beamline BM23.

Proton-Selective Coating Enables Fast-Kinetics High-Mass-Loading Cathodes for Sustainable Zinc Batteries

March 29, 2024

2D polyimine nanomembrane with high ion selectivity enables a high-kinetics electrochemistry transition for aqueous zinc batteries

Research:

The pressing need for sustainable and scalable energy storage solutions has spurred the burgeoning development of aqueous zinc batteries (AZBs). However, the presence of kinetics-sluggish Zn²⁺ as the dominant charge carriers in AZB cathodes leads to suboptimal charge-storage capacity and durability, which poses a significant hurdle in the practical implementation of AZBs.

The scientists from TU Dresden and MPI Halle, together with collaborators, discover that an ultrathin 2D polyimine membrane (2DPM) featured by dual ion-transport nanochannels and densely distributed proton-conduction groups facilitates rapid and selective proton passing within the typical AZB electrolyte medium. Permeation measurements reveal 2DPM with a high H⁺ flux exceeding 0.9 mol m⁻² h⁻¹ and an excellent H⁺/Zn²⁺ transport selectivity of 140.7. Consequently, we achieve a distinctive electrochemistry transition shifting from sluggish Zn²⁺-dominated to fast-kinetics H⁺-dominated Faradic reactions within high-mass-loading AZB cathodes by using 2DPM as an interfacial coating. Combining 2DPM with a NaV₃O₈·1.5H₂O cathode (10 mg cm⁻²) maximizes the realization of theoretical capacity (increasing from 288.8 to 450.5 mAh g⁻¹). More importantly, the electrode shows an exceptionally high areal capacity of 4.5 mAh cm⁻² and state-of-the-art energy density of 33.8 Wh m⁻², along with enhanced cycling stability (68.6% vs. 87.8% after 1,000 cycles). Using the 2DPM coating, they further demonstrate the interfacial proton-selective transport for different cathodes (e.g., ε-MnO₂ and α-MoO₃) and varying aqueous electrolytes (e.g., 2 M ZnSO₄ and 20 m ZnCl₂), validating its universality for developing reliable aqueous batteries.

Acknowledgements: This work was financially supported by European Union’s Horizon Europe research and innovation programme (ERC Starting Grant, BattSkin, 101116722), European Union’s Horizon 2020 research and innovation programme (LIGHT-CAP 101017821), the ERC Consolidator Grant (T2DCP, NO. 819698), German Research Foundation (DFG) within the Cluster of Excellence, CRC 1415 (Grant No. 417590517), and Polymer-based Batteries (SPP 2248, RACOF-MMIS). The authors acknowledge the use of the facilities in the Dresden Center for Nanoanalysis (DCN) at the Technische Universität Dresden, the GWK support for providing computing time through the Center for Information Services and High-Performance Computing (ZIH) at TU Dresden, beam time allocation at beamline P02.1 and P65 at the PETRA III synchrotron (DESY, Hamburg, Germany), and beam time allocation at beamline 3C SAXS-I and 9A U-SAXS at the Pohang Accelerator Laboratory (PLS-II).

Reference: Guo, Q., Li, W., Li, X. et al. Proton-selective coating enables fast-kinetics high-mass-loading cathodes for sustainable zinc batteries. Nat. Commun. 15, 2139 (2024). https://doi.org/10.1038/s41467-024-46464-9.

On-liquid-gallium surface synthesis of ultra-smooth thin films of conductive metal-organic frameworks

March 28, 2024

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) refer to a class of layer-stacked conductive MOFs linked by square-planar complexes with in-plane π-extended conjugation and out-of-plane van der Waals interaction. The unique charge transport properties and the structural/compositional diversity result in 2D c-MOFs with numerous intriguing physical properties, further enabling them for broad (opto-)electronic applications. However, the currently synthesized 2D c-MOF films suffer from rough film surface (root-mean-square roughness (R_q) ranges from 20 to 10³ Å) owing to the poor controllability of precursor nucleation. Researchers from the group of Prof. Xinliang Feng and collaborators a general chemical vapor deposition (CVD) method based on an on-liquid-gallium surface synthesis (OLGSS) strategy for the growth of nine representative ultra-smooth 2D c-MOF thin films with the R_q down to ~2 Å, signifying at least ten-fold improvement in surface flatness compared to the reported works. As proposed by the theoretical calculations, the surpassing adsorption capacity of the adsorbed aromatic ligands with face-on orientation on the Ga surface ensures the formation of the initial flat 2D c-MOF layer. Furthermore, the high adhesion energy between 2D c-MOF layers and Ga permits the film growth following the layer-by-layer mode, thereby yielding a uniform thin film with ultra-smooth surface. Owing to the highly improved interface contact, the contact resistance in the integrated devices of OLGSS films can be reduced by more than 10 times compared to that of the samples synthesized by reported method. In addition, the van der Waals heterostructures (vdWHs) constructed by few-layer OLGSS 2D c-MOF layer and monolayer MoS₂ reveal large modulations of the photoluminescence (PL) properties and work function (WF), which highlights the potential of OLGSS films as building blocks for creating unique vdWHs and uncovering novel interfacial phenomena. This work develops a robust OLGSS strategy that affords a feasible access to versatile operable 2D c-MOF films with ultra-smooth surfaces as well as their vdWHs and breaks one synthetic bottleneck of conductive MOFs for (opto-)electronic devices.

Reference: Jinxin Liu, Yunxu Chen, Xing Huang, Yanhan Ren, Mike Hambsch, David Bodesheim, Darius Pohl, Xiaodong Li, Marielle Deconinck, Bowen Zhang, Markus Löffler, Zhongquan Liao, Fengxiang Zhao, Arezoo Dianat, Gianaurelio Cuniberti, Yana Vaynzof, Junfeng Gao*, Jingcheng Hao, Stefan C. B. Mannsfeld, Xinliang Feng*, Renhao Dong*. On-liquid-gallium surface synthesis of ultrasmooth thin films of conductive metal–organic frameworks. Nat. Synth. (2024). DOI: 10.1038/s44160-024-00513-9.

Acknowledgements: This work was financially supported by National Natural Science Foundation of China (22272092), ERC starting grant (FC2DMOF, number 852909), ERC Consolidator grant (T2DCP), SFB-1415 (number 417590517), GRK2861 (number 491865171), EMPIR-20FUN03-COMET, and by the German Science Council, Center for Advancing Electronics Dresden (CFAED). This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (ERC grant agreement number 714067, ENERGYMAPS). We acknowledge the European Synchrotron Radiation Facility (ESRF) for provision of synchrotron radiation facilities and we thank O. Konovalov for assistance and support in using beamline ID10. We acknowledge Elettra Sincrotrone Trieste for providing access to its synchrotron radiation facilities and for financial support under the IUS internal project. We thank L. Barba for assistance in using beamline XRD1. We acknowledge Dresden Center for Nanoanalysis (DCN) at TUD. R.D. thanks the Taishan Scholars Program of Shandong Province (tsqn201909047) and the Natural Science Foundation of Shandong Province (ZR2023JQ005). We thank Z. Wang for his help with TEM measurements. J.L. gratefully acknowledges funding from the Alexander von Humboldt Foundation.

Prof. Xinliang Feng is elected as a member of the Leopoldina

March 6, 2024

Prof. Xinliang Feng, Director at the Max Planck Institute of Microstructure Physics in Halle Halle and Professor at the Technical University of Dresden, has been elected as an ordinary member of the Chemistry Division of the German Academy of Sciences Leopoldina. Xinliang Feng was elected as a new member by the Division and the Presidium of the Leopoldina in a multi-stage process. Feng's future tasks will include providing scientific policy advice and contributing to politically and socially relevant issues.

“It is an immense honor to have been elected as a member of a distinguished academy such as Leopoldina. I am humbled to be included among the ranks of so many esteemed figures from scientific history. This membership opens up wonderful opportunities for collaboration with my esteemed colleagues in the academy, and I am eager to contribute to the advancement of science alongside them in the future.“, said the newly appointed member.  

Feng's research focuses on exploring precision chemistry and synthesis to discover new materials, including organic 2D crystals, carbon nanostructures, and graphene nanoribbons with emergent phenomena and properties to address global challenges.

New materials play a key role in addressing society's challenges and providing new opportunities. For instance, clean energy, clear water, environmental protection, and sustainable development require breakthrough discovery and application of exotic materials. In addition, new materials provide unique opportunities for emerging information technology, and artificial intelligence, among others.

About Prof. Xinliang Feng

Prof. Xinliang Feng is a chemist and professor at the Technical University of Dresden specializing in 2D materials and functional devices, especially graphene. Since 2014, as part of the Cluster of Excellence Centre for Advancing Electronics Dresden (cfaed) he has been Professor of Molecular Functional Materials. Since 2021 he has been a Scientific Member of the Max Planck Society and Director of the Department of Synthetic Materials and Functional Devices (SMFD) at the Max Planck Institute of Microstructure Physics in Halle. He is one of the most cited researchers in chemistry and materials science, Clarivate Analytics. Feng has received many awards and has published more than 700 research articles, which attracted more than 109,000 citations and an H-index of 164 (Google Scholar).

About the German National Academy of Sciences Leopoldina

The Leopoldina originated in 1652 as a classical scholarly society and now has 1,600 members from almost all branches of science. In 2008, Leopoldina was appointed as the German National Academy of Sciences and, in this capacity, was invested with two major objectives: representing the German scientific community internationally, and providing policymakers and the public with science-based advice. The Leopoldina champions the freedom and appreciation of science. It promotes a scientifically enlightened society and the responsible application of scientific insight for the benefit of humankind and the natural world. In its interdisciplinary discourse, the Academy transcends thematic, political, and cultural boundaries.

Source: https://www.mpi-halle.mpg.de/xinliang-feng-elected-as-a-leopoldina-member?c=178485

Dr. Minghao Yu receives the status of TUD Young Investigator

February 26, 2024

On February 13, 2024, the Rectorate based on the support of the Faculty of Chemistry and Food Chemistry has approved Dr. Minghao Yu’s status of TUD Young Investigator. Congratulations!

The “TUD Young Investigator” status strengthens excellent, independent junior research group leaders by fostering their integration into the faculties and offering a qualification program FAST FORWARD tailored to their particular needs. This scheme aims to counteract the structural disadvantages sometimes experienced by this group of researchers due to their lack of defined status and inadequate or nonexistent connection to a faculty.

For more information, please refer to: https://tu-dresden.de/forschung-transfer/wissenschaftlicher-nachwuchs/nach-der-promotion/tud-young-investigators

Dr. Muhammad Imran, hailing from Pakistan, has been honored with the prestigious Marie Skłodowska-Curie Postdoctoral Fellowship

February 14, 2024

Dr. Imran's academic journey has been marked by notable achievements. In 2017, he was awarded the esteemed Fulbright Fellowship to pursue his PhD studies in the United States. He successfully completed PhD in Chemistry from Lehigh University, PA. His doctoral research primarily focused on the synthesis and device applications of open-shell molecular materials.

Following his PhD, Dr. Imran embarked on his postdoctoral endeavors, joining SFMD at the Max Planck Institute of Microstructure Physics as an Alexander von Humboldt Postdoctoral Fellow in 2023. His research interests revolve around the synthesis of non-Kekulé hydrocarbons, with a keen focus on exploring their intrinsic spin properties for quantum applications, including quantum computing.

Dr. Imran's dedication and scholarly pursuits exemplify a commitment to advancing the frontiers of scientific knowledge and innovation. His contributions are poised to make significant impact in the field of materials science and quantum technologies.

Dr. Wenhui Niu receives a Minerva Fast-Track Fellowship

January 30, 2024

Dr. Wenhui Niu was awarded a Minerva Fast Track position by the Max Planck Society to establish her first research group “Quantum Chiral Nanocarbons” at the Max Planck Institute of Microstructure Physics in Halle.

Chiral nanocarbons have attracted growing attention due to their exotic 3D structure, inherent chirality, and intriguing optoelectronic properties, in particular, their unique chiral-induced spin selectivity (CISS) effect. Due to the unique structural tunability and the specificity of quantum sensing, chiral nanocarbons have the potential to be a transformative tool in the next generation of quantum applications.

Within the Minerva Fast-Track Fellowship, the research interests of Wenhui and her team will focus on (1) discovery of the chiral structure-CISS effect relationship; A series of novel chiral nanocarbons will be synthesized as the molecular platform and their individual spin polarization will be discovered where we will gain valuable insights of how the chiral structure will affect the CISS effect. As a result, design principle of chiral nanocarbons for the CISS effect will be established aiming to achieve high spin polarization. (2) Development of chiral spintronics based on helical carbon nanostructures; Based on CISS effect, the chiral spintronics devices can control the overall electrical resistance by applying magnetic field to manipulate the electron’s spin and spin polarized current. Utilizing chiral molecules with high spin polarization, one highly interesting target is developing the high-performance chiral spintronics with large spin polarized current and good spin current manipulation. (3) Exploitation of Spin-controlled chemistry; For chiral molecules, the electron spin is strongly coupled to the molecular frame. Therefore, electron transfer and electron rearrangement of chiral reactants (and intermediates) might be affected during the reaction based on CISS effect, which can be used to provide spin control over chemical reactions, enabling to control the reaction path and achieve enantioselective synthesis.

Dr. Wenhui Niu comes from Liaoning, China. She studied polymer engineering at Sichuan University and obtained her Bachelor’s degree in 2016. From 2016, she started her PhD in chemistry from Shanghai Jiao Tong University under the supervision of Prof. Yiyong Mai. Between 2017 and 2020, she joined Prof. Xinliang Feng’s group as an exchange PhD student. In 2021, she received her PhD degree and joined the group of Prof. Xinliang Feng and continued her academic research as a postdoctoral fellow at Technische Universität Dresden for one year. After that, she joined the Max Planck Institute of Microstructure Physics as a research group leader, where she focuses on the exploitation of novel chiral nanographenes with excellent chiroptical properties and distinct spin polarizability. Since January 2024, Wenhui is leading the “Quantum Chiral Nanocarbons” group as Minerva Fast-Track fellow.

Workshop on Two Dimensional Conjugated MOFs (2D c-MOFs) and Coordination Nanosheets

December 13, 2023

Our onsite workshop on Two Dimensional Conjugated MOFs (2D c-MOFs) and Coordination Nanosheets brought together an esteemed gathering of over 40 researchers from around the world on December 11th and 12th, 2023.

Esteemed speakers hailing from prestigious research institutions in Germany, France, the United Kingdom, Korea, and Japan shared groundbreaking insights spanning a wide spectrum of disciplines. The symposium delved into the realms of coordination chemistry, organic and inorganic synthesis, nanoscience, electronics, and the condensed physics of 2D c-MOFs and coordination nanosheets. The 21 invited speakers enriched the event with their expertise, engaging in vibrant discussions and presenting the very latest developments in their respective fields.

The masterful coordination of this symposium was orchestrated by the adept Prof. Xinliang Feng, whose affiliations include TU Dresden and MPI of Microstructure Physics, Halle, and the accomplished Dr. Yang from the University of Strasbourg and TU Dresden.

Beyond being a platform for the dissemination of cutting-edge research, this symposium underscored the collective pursuit of knowledge and innovation within the global scientific community. The collaborative spirit that permeated the event not only showcased the most recent advancements in organic 2D materials but also served as a beacon for future collaborative endeavors that transcend geographical boundaries. The symposium stands as a testament to the shared commitment to advancing our understanding of 2D c-MOFs and coordination nanosheets.

Dr. Minghao Yu has been admitted as the Fellow of the Young Academy of Europe

December 8, 2023

On 21^st November 2023, the Selection Committee and the Board of the Young Academy of Europe (YAE) have unanimously decided to admit Dr. Minghao Yu as a new YAE member.

The Young Academy of Europe is organized as a bottom-up initiative of a dynamic and innovative group of recognized European young scholars with outspoken views about science and science policy. It is a pan-European initiative of young scientists for networking, scientific exchange, and science policy.

For more information, please refer to: https://yacadeuro.org/

Congratulations to Lin Yang for successfully defending his PhD

November 28, 2023

Lin Yang successfully defended his PhD on "Precision Synthesis of Helical Non-Benzenoid Nanographenes and Magnetic Nanographenes" on November 27, 2023. Congratulations Dr. Yang!

Workshop of the second "Advances in Precision Carbon Nanostructures" (2nd PCNano)

November 23, 2023

On November 22^nd, an enlightening workshop on the 2^nd “Advances in Precision Carbon Nanostructures (PCNano)” took place in Dresden, showcasing the forefront of research in this research field. The event featured four distinguished speakers from around the globe, each delivering outstanding presentations:

• Michael Haley, University of Oregon (USA): The Interplay Between Antiaromaticity and Diradical Character in Diarenoindacenes and Diindenoarenes
• Konstantin Amsharov, Halle University (DE): Towards direct synthesis of carbon based nanostructures on metal oxide surfaces
• Michal Juríček, University of Zurich (CH): Taming and unleashing the reactivity of nanographene π-radicals
• Milan Kivala, Heidelberg University (DE): Alkynes as a Versatile Entry into Fascinating Polycyclic Landscapes

Additionally, local representative speakers (Dr. Ji Ma, Mr. Sebastian Obermann, Dr. Wenhui Niu, Dr. Jin-Jiang Zhang) shared the latest achievements from the chair. Their presentations covered the topics of magnetic nanocarbons, precision graphene nanoribbons, and boron-doped nanographene.

Organized by Prof. Xinliang Feng and Dr. Ji Ma at TU Dresden & MPI of Microstructure Physics, Halle, the 1^st PCNano was made online on January 20th and 21st, 2022 in honor of Prof. Klaus Müllen’s 75th birthday. Plans are underway to organize the 3^rd edition in the near future, promising continued exploration and dissemination of groundbreaking advancements in precision carbon nanostructures.

For the detailed program, please click here.

HIGHLY CITED RESEARCHER 2023

Mingchao Wang received the ACS Rising Talents Prize

November 9, 2023

Dr. Mingchao Wang receives the American Chemical Society (ACS) Rising Talents Prize at the Smart Engineering & Materials International Summit 2023. Congratulations.

Prof. Jong-Beom Baek - Guest Professor/Mercator Fellow at TU Dresden

September 22, 2023

Jong-Beom Baek is a distinguished professor/director of the Department of Energy and Chemical Engineering/Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), South Korea. His current research interests include the syntheses of two- and three-dimensional high-performance organic network structures and the chemical modifications of carbon-based materials for multifunctional applications, including energy conversion and storage.

Prof. Baek will be a guest professor at TUD from September 2023 to August 2024.

Source: https://tu-dresden.de/mn/chemie/sfb1415/forschung/gastwissenschaftler?set_language=en

Dr. Minghao Yu receives ERC Starting Grant of 1.5 Million EUR to advance sustainable batteries

September 5, 2023

With his "BattSkin” project (Practical Magnesium Batteries Enabled by 2D Crystalline Polymer-Based Artificial Electrode Skins), chemist Dr. Minghao Yu aims to advance research into a new and more sustainable battery technology over the next five years. The focus will be on advancing the promising magnesium batteries, using precise polymer chemistry to govern the interfacial ion dynamics. Magnesium batteries are considered top candidates in the race for the next generation of battery technologies due to their low cost, high efficiency, sustainability, and safety. So far, they are still the subject of fundamental research, since charge transfers at the interface in particular still pose problems in practical implementation.

In his ERC project, Dr. Minghao Yu will work on a groundbreaking concept in which molecule-specific customizable 2D crystalline polymers (2DCPs) serve as artificial electrode 'skins', a kind of interphase, to regulate interfacial ion transport and make magnesium batteries ready for application. “With the project, I expect to strengthen my research independence by assembling a skilled and competitive research team with diverse expertise. Meanwhile, the scientific outcomes will earn me a unique academic reputation in the field of next-generation sustainable batteries,”Yu is convinced.

The Chinese-born chemist has been leading a research group at cfaed (Center for Advancing Electronics Dresden) since March 2019 and works at the Faculty of Chemistry and Food Chemistry at TU Dresden. He has already been listed several times in Clarivate Analytics’ list of Highly Cited Researchers and has received numerous other awards.

Source TUD Public Relations Office : https://tu-dresden.de/tu-dresden/newsportal/news/erc-starting-grants-drei-junge-tud-wissenschaftler-unter-den-ausgezeichneten?set_language=de

Website of Dr. Minghao Yu

Thiophene Backbone Enables Two-Dimensional Poly(arylene vinylene)s with High Charge Carrier Mobility

August 17, 2023

Linear conjugated polymers have garnered considerable interest over the past few decades. Despite the presence of intrachain π-delocalization, the impediment to their transport arises from interchain hopping interactions. In contrast, two-dimensional (2D) conjugated polymers, as represented by 2D p-conjugated covalent organic frameworks (2D c-COFs), can provide multiple conjugated strands to enhance the delocalization of charge carriers in space. Herein, we demonstrate the first example of thiophene-based 2D poly(arylene vinylene)s (PAVs, 2DPAV-BDT-BT and 2DPAV-BDT-BP, BDT= benzodithiophene, BT=bithiophene, BP=biphenyl) via Knoevenagel polycondensation. Compared with 2DPAV-BDT-BP, the fully thiophene-based 2DPAV-BDT-BT exhibits enhanced planarity and p-delocalization with a small band gap (1.62 eV) and large electronic band dispersion, as revealed by the optical absorption and density functional theory calculations. Remarkably, temperature-dependent terahertz spectroscopy discloses a unique band-like transport and outstanding room-temperature charge mobility for 2DPAV-BDT-BT (65 cm²V⁻¹s⁻¹), which far exceeds that of the linear PAVs, 2DPAV-BDT-BP, and the reported 2D c-COFs in the powder form. This work highlights the great potential of thiophene-based 2D PAVs as candidates for high-performance opto-electronics.

Reference: Yamei Liu, Heng Zhang, Hongde Yu, Zhongquan Liao, Silvia Paasch, Shunqi Xu,* Ruyan Zhao, Eike Brunner, Mischa Bonn, Hai I. Wang,* Thomas Heine, Mingchao Wang,* Yiyong Mai,* Xinliang Feng*.

Acknowledgements: L., H. Z., H. Y. contributed equally to this work. This work was financially supported by ERC grant (T2DCP, No. 819698), DFG project (CRC 1415, No. 417590517), European Union's Horizon 2020 (PROGENY, No. 899205; Graphene Flagship Core3, No. 881603; EMERGE, No. 101008701), and Center for Advancing Electronics Dresden. Y.M.L. appreciates fellowship support from the Chinese Scholarship Council (CSC). Y.M. acknowledges the financial support from National Natural Science Foundation of China (52073173 and 22225501), and National Key R&D Program of China (2021YFB4001100). We thank Dresden Center for Nanoanalysis (DCN) for the use of facilities and Matthias Kluge for TGA measurement. We appreciate Dr. Yang Lu, Dr. Yannan Liu, Albrecht Wäntig and Shaik Ghouse for helpful discussions. H.Y. and T.H. acknowledge the Alexander von Humboldt Foundation for financial support and the Centre for Information Services and High Performance Computing (ZIH) at TU Dresden for the provided computational resources. The Instrumental Analysis Center at Shanghai Jiao Tong University is also acknowledged.

Prof. Jayasundera Bandara received the prestigious Humboldt Research Fellowship

August 7, 2023

The Alexander von Humboldt Foundation has granted a research fellowship to Prof. Jayasundera Bandara (Research Professor at the National Institute of Fundamental Studies, Sri Lanka) for a renewed research stay. By being granted this fellowship, Prof. Bandera will receive financial support for 3 months to carry out his research in the research group of Prof. Xinliang Feng at Technische Universität Dresden.

Bottom-up solution synthesis of graphene nanoribbons with precisely engineered nanopores

June 28, 2023

Nanopores in Graphene nanoribbons (GNRs)

Bottom-up chemical synthesis of graphene nanoribbons (GNRs) has attracted enormous attention from the scientific community in the last decade, providing various atomically precise GNR structures with tunable physicochemical properties. Besides the width and edge structure control, the introduction of well-defined nanopores into GNRs has been recently recognized as an important parameter to finely tune their electronic structures, topologies, opto-electronic and thermoelectric transport properties. However, the precise synthesis of porous GNR (pGNR) with uniform nanopores is still in its infancy especially in solution due to the lack of efficient synthetic strategies and suitable precursor design.

The scientists from MPI Halle and TU Dresden, together with collaborators, have demonstrated the first successful bottom-up solution synthesis of fully conjugated pGNR containing periodic well-defined nanopores. The key design here is making the tailor-made polyphenylene precursor with pre-installed hexagonal nanopores, which allows us to access the pGNR with intact conjugation and precisely embedded nanopores with a diameter of 0.6 nm and an adjacent-pore-distance of 1.7 nm. DFT simulation suggests that the nanopores in pGNR can effectively modulate its electronic structure and energy levels distribution without interrupting the conjugation of the ribbon. This study paves the way for the solution synthesis of porous GNRs with defined nanopores, tunable bandgaps, and liquid-phase processability, enabling their potential applications in sensing and thermoelectric devices. This fruitful work of the joint research has been now published in the renowned journal “Angewandte Chemie International Edition”.

Acknowledgements: This research was financially supported by the National Natural Science Foundation of China (22225501 and 52203268), the EU Graphene Flagship (Graphene Core 3, 881603), H2020-MSCA-ITN (ULTIMATE, No. 813036), the Center for Advancing Electronics Dresden (cfaed), H2020-EU.1.2.2.- FET Proactive Grant (LIGHT-CAP, 101017821), the DFG-SNSF Joint Switzerland-German Research Project (EnhanTopo, No. 429265950), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDB33000000 and XDB33030300), and the DFG funded Cluster of Excellence “Matters of Activity” (No. 390648296).

Reference: Niu, Wenhui, Fu, Yubin, Serra, Gianluca, Liu, Kun, Droste, Jörn, Lee, Yeonju, Ling, Zhitian, Xu, Fugui, González, José D. Cojal, Lucotti, Andrea, Rabe, Jürgen P., Hansen, Michael Ryan, Pisula, Wojciech, Blom, Paul W. M., Palma, Carlos-Andres, Tommasini, Matteo, Mai, Yiyong, Ma, Ji, Feng, Xinliang, Angew. Chem. Int. Ed. 2023, e202305737.

Exceptionally high charge mobility in phthalocyanine-based poly(benzimidazobenzophenanthroline)-ladder-type two-dimensional conjugated polymers

June 28, 2023

Two-dimensional conjugated polymers (2D CPs), composed of multi-strands of linear CPs with extended in-plane π-conjugation, are emerging crystalline semiconducting polymers for organic (opto-)electronics. They are represented by 2D p-conjugated covalent organic frameworks, which typically suffer from poor p-conjugation and thus low charge carrier mobilities. In order to overcome this limitation, researchers from the group of Prof. Xinliang Feng and collaborators have demonstrated the first examples of poly(benzimidazobenzophenanthroline) (BBL)-ladder-type crystalline 2D CPs (based on phthalocyanine, termed as 2DCP-MPc, with M = Cu or Ni) showing unique band transport and outstanding charge carrier mobilities. To optimize the conjugation degree in 2D CPs, they investigate various conjugated linkages by theoretical computations on representative model compounds, and find that the BBL-ladder-type structure exhibits delocalized p-electrons with a narrow HOMO-LUMO  gap. 2DCP-MPcs are synthesized via an acid-modulated polycondensation between octaaminophthalocyaninato metal(II) and naphthalenetetracarboxylic dianhydride under solvothermal conditions. 2DCP-MPcs display narrow optical bandgaps of ~1.3 eV. Density functional theory calculations unveil strongly dispersive energy bands with small electron–hole reduced effective masses of ~0.15 m₀ for the layer-stacked 2DCP-MPcs. Terahertz spectroscopy reveals the band transport of Drude-type free carriers in 2DCP-MPcs with exceptionally high sum mobility of electrons and holes of ~970 cm²V^-1s^-1 at 298 K (and ~1390 cm²V^-1s^-1 at 78 K), which significantly exceeds that of linear and 2D CPs.

 

Reference: Mingchao Wang, Shuai Fu, Petko St. Petkov, Yubin Fu, Zhitao Zhang, Yannan Liu, Ji Ma, Guangbo Chen, Sai Manoj Gali, Lei Gao, Yang Lu, Silvia Paasch, Haixia Zhong, Hans-Peter Steinrück, Enrique Cánovas, Eike Brunner, David Beljonne, Mischa Bonn, Hai I. Wang*, Renhao Dong*, Xinliang Feng*. Exceptionally high charge mobility in phthalocyanine-based poly(benzimidazobenzophenanthroline)-ladder-type two-dimensional conjugated polymers. Nat. Mater. 2023, DOI: 10.1038/s41563-023-01581-6.

Acknowledgements: This work was financially supported by ERC Grants (T2DCP, no. 819698; FC2DMOF, no. 852909), DFG projects (CRC 1415, no. 417590517; SPP 2248, RACOF-MMIS), EU Graphene Flagship (Core3, no. 881603) and Center for Advancing Electronics Dresden. S.F. acknowledges fellowship support from the Chinese Scholarship Council (CSC). We thank Dresden Center for Nanoanalysis (DCN) and P. Formanek (IPF, Dresden) for the use of facilities. A portion of this work was performed on the Steady High Magnetic Field Facilities, High Magnetic Field Laboratory, CAS. We appreciate C. Naisa, S. Xing, W. Niu, S. Park, J. Liu, Z. Zhang, P. Zhang, B. Zhang and S. Revueta for helpful discussions and measurements. M.W. specially acknowledges J. Cui. R.D. thanks Taishan Scholars Program of Shandong Province (tsqn201909047) and National Natural Science Foundation of China (22272092). E.C. acknowledges financial support from MCIN/AEI grant PID2019-107808RA-I00 and Comunidad de Madrid grants 2021-5A/AMB-20942 and P2018/NMT-451. P.S.P. and Y.F. acknowledge the Center for Information Services and High Performance Computing (ZIH) at TU Dresden for providing the high-performance computing resources.

Near IR bandgap semiconducting 2D conjugated metal-organic framework with rhombic lattice and high mobility

March 8, 2023

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) are emerging as a unique class of electronic materials but have been found to be intrinsically metallic or possess a low bandgap. 2D c-MOFs with open band gaps in the Vis-NIR and high carrier mobilities are still rare, limiting the application of 2D c-MOFs in logic devices. The researchers of the group of Prof. Xinliang Feng in collaboration with researchers from Stockholm University and IMDEA Nanociencia (Madrid) report a new ligand design that increases the out-of-plane mobility while keeping an open band gap. The D_2h-symmetric π-extended ligand (OHPTP), and the derived rhombic 2D c-MOF single crystals (Cu₂(OHPTP)) are unambiguously characterized on the single crystal level by continuous rotation electron diffraction (cRED) revealing the orthorhombic crystal structure at the atomic level with an unique AB layer stacking. Electrical characterization and terahertz spectroscopic studies show that Cu₂(OHPTP) is a p-type semiconductor with an indirect band gap of ~0.50 eV and a high electrical conductivity of 0.10 S cm^-1 as well as a high charge carrier mobility of ~10.0 cm²V^-1s^-1. The open bandgap and high out-of-plane band dispersion are further confirmed by DFT calculations. The findings have been published in the journal Angewandte Chemie International Edition.

This work was financially supported by the ERC starting grant (FC2DMOF, No. 852909), ERC Consolidator Grant (T2DCP, No. 819698), DFG project (CRC-1415, No. 417590517), EMPIR-20FUN03-COMET, as well as the German Science Council and Center for Advancing Electronics Dresden (cfaed). Further support was provided by the Taishan Scholars Program of Shandong Province (tsqn201909047) and the National Natural Science Foundation of China (22272092); the MCIN/AEI grant PID2019-107808RA-I00 and Comunidad de Madrid grants 2021-5A/AMB-20942 & P2018/NMT-451; the MSCA HORIZON 2020 funding via 101030872 – PhoMOFs grant and the Swedish Research Council Formas (2020-00831), and the Swedish Research Council (VR, 2022-02939).

Reference: Lukas Sporrer, Guojun Zhou, Mingchao Wang, Vasileios Balos, Sergio Revuelta, Kamil Jastrzembski, Markus Löffler, Petko Petkov, Thomas Heine, Angieszka Kuc, Enrique Cánovas, Zhehao Huang, Xinliang Feng, Renhao Dong, Near IR bandgap semiconducting 2D conjugated metal-organic framework with rhombic lattice and high mobility, https://doi.org/10.1002/anie.202300186.

Ion-selective 2D polymer membrane works as the battery electrode skin

March 8, 2023

The fast-kinetics, high-potential, and large-capacity anion-intercalation chemistries of graphite have the potential to construct sustainable batteries with promising energy and power breakthroughs. Yet, the poor durability hinders their deployment in practical batteries due to the detrimental electrolyte decomposition and cation/solvent co-intercalation.

The scientists from TU Dresden and MPI Halle, together with collaborators, report the use of an ultrathin, positively charged two-dimensional poly(pyridinium salt) membrane (denoted C2DP) as the graphite electrode skin to overcome the critical durability problem. The large-area C2DP membrane (28 cm²) enables the conformal coating on the graphite electrode, alleviating the electrolyte decomposition and the formation of the anion-blocking passivation layer. The dense face-on oriented single crystals with the ultrathin thickness (20 nm) and cationic backbones allow C2DP with high anion-transport capability (PF₆⁻ diffusivity: ~10⁻⁷ cm² s⁻¹) and selectivity (PF₆⁻ transference number of the polypropylene separator vs. the C2DP-loaded polypropylene separator, 0.17 vs. 0.51). Such desirable anion-transport properties of C2DP prevent the cation/solvent co-intercalation into the graphite electrode and suppress the consequent structure collapse. An impressive PF₆⁻-intercalation durability is demonstrated for the C2DP-covered graphite electrode, with capacity retention of 92.8 % after 1,000 cycles at 1 C and Coulombic efficiencies of > 99%, which is the best among the reported anion-intercalation chemistries of graphite in organic electrolytes. The study showcases the feasibility of constructing artificial ion-regulating electrode skins with precisely customized two-dimensional polymers, which offers viable means to promote problematic battery chemistries that rely on complex charge carrier ions.

Reference : Davood Sabaghi, Zhiyong Wang, Preeti Bhauriyal, Qiongqiong Lu, Ahiud Morag, Daria Mikhailovia, Payam Hashemi, Dongqi Li, Christof Neumann, Zhongquan Liao, Anna Maria Dominic, Ali Shaygan Nia, Renhao Dong, Ehrenfried Zschech, Andrey Turchanin, Thomas Heine, Minghao Yu, and Xinliang Feng. Nature Communications 2023, 14, 760.

Acknowledgements: this work was financially supported by European Union’s Horizon 2020 research and innovation programme (GrapheneCore3 881603, LIGHT-CAP 101017821), M-ERA.NET and Sächsisches Staatsministerium für Wissenschaft und Kunst (HYSUCAP 100478697 & Sonderzuweisung zur Unterstützung profilbestimmender Struktureinheiten), and German Research Foundation (DFG) within the Cluster of Excellence, CRC 1415 (Grant No. 417590517), and Polymer-based Batteries (SPP 2248, RACOF-MMIS). P.B. acknowledges the Alexander-von-Humboldt foundation for funding. R.D. appreciates the funding support from ERC starting grant (FC2DMOF, No. 852909). C.N. and A.T. acknowledge financial support of the DFG through a research infrastructure grant INST 275/357-1 FUGG and the Thüringer Ministerium für Wirtschaft, Wissenschaft und Digitale Gesellschaft (TMWWDG) and the Thüringer Aufbau Bank (TAB) within the project LiNaKon (2018 FGR 0092). The authors acknowledge the use of the facilities in the Dresden Center for Nanoanalysis (DCN) at the Technische Universität Dresden, the GWK support for providing computing time through the Center for Information Services and High-Performance Computing (ZIH) at TU Dresden, beam time allocation at beamline P02.1 at the PETRA III synchrotron (DESY, Hamburg, Germany), beam time allocation at beamline ID13 of the European Synchrotron Radiation Facility (ESRF), and the Helmholtz-Zentrum Berlin für Materialien und Energie for the allocation of synchrotron radiation beamtime (beamline U41-TXM).

Exceptionally clean single-electron transistors from solutions of molecular graphene nanoribbons

February 3, 2023

Graphene nanoribbons in quantum electronics and spintronics

Graphene has been called the wonder material, and its mechanical and electric properties never cease to amaze. The properties of graphene electronic quantum devices could be custom-tailored, if we could control the geometry of its edges at the single-atom level. Such atom-precise graphene devices would yield excellent building blocks for quantum electronics, and spintronics.

The scientists from TU Dresden/MPI Halle/SJTU/Oxford University have joined forces to create atomically-perfect graphene nanoribbons in huge quantities, and integrated them into exceptionally clean electronic nanodevices. The result is a graphene field-effect transistor where it is possible to identify the coupling of electrons and single vibrational modes. The devices are remarkably simple to make, and allow skipping many of the time-consuming and expensive steps necessary for comparable carbon nanotube devices. As a consequence, such results could usher a new era for quantum electronic devices. This fruitful work of the joint research has been now published in the renowned journal “Nature Materials”.

This research is a joint collaboration between scientists from the Technische Universität Dresden (TUD), Max Planck Institute of Microstructure Physics (MPI Halle), Shanghai Jiao Tong University (SJTU) and Oxford University. The authors gratefully thank the European Union (ERC-CoG-773048-MMGNRs), the Royal Society (University Research Fellowship and grant), the Engineering and Physical Sciences Research Council (EP/N017188/1-QuEEN), the Norwegian State Educational Loan Fund (Keeley and Norwegian scholarships to Wadham College Oxford) and the Max Planck Gesellshaft (MPG) for financial support. We thank University of Norwich for the use of the atomic force microscopy instrument and Oxford-Advanced Research Computing (ARC) for computational time.

Reference: Niu, W.; Sopp, S.; Lodi, A.; Gee, A.; Kong, F.; Pei, T.; Gehring, P.; Nägele, J.; Lau, C. S.; Ma, J.; Liu, J.; Narita, A.; Mol, J.; Burghard, M.; Müllen, K.; Mai, Y.; Feng, X.; Bogani, L., Exceptionally clean single-electron transistors from solutions of molecular graphene nanoribbons. Nature Materials 2023, 22 (2), 180-185.

Congratulations to Fupeng Wu for successfully defending his PhD

January 10, 2023

Fupeng Wu successfully defended his PhD on "Precision Synthesis of Nanographenes with Intrinsic π-Magnetism" on January 6, 2023. Congratulations Dr. Wu!

Precise tuning of interlayer electronic coupling in layered conductive metal-organic frameworks

December 2, 2022

Electrically conductive metal-organic frameworks (MOFs), such as two-dimensional conjugated MOFs (2D c-MOFs), have attracted increasing interests for (opto)-electronics and spintronics. They generally consist of van der Waals stacked layers and exhibit layer-depended electronic properties. While considerable efforts have been made to regulate the charge transport within a layer, precise control of electronic coupling between layers has not yet been achieved. The researchers from the group of Prof. Xinliang Feng report a novel strategy to precisely tune interlayer charge transport in 2D c-MOFs via side-chain induced control of the layer spacing. They design hexaiminotriindole ligands allowing programmed functionalization with tailored alkyl chains (HATI_CX, X = 1,3,4; X refers to the carbon numbers of the alkyl chains) for the synthesis of semiconducting Ni₃(HATI_CX)₂. The layer spacing of these MOFs can be precisely varied from 3.40 to 3.70 Å, leading to the widened band gap, suppressed carrier mobilities, and significant improvement of the Seebeck coefficient. With this demonstration, we further achieve a record-high thermoelectric power factor of 68 ± 3 nW m⁻¹ K⁻² in Ni₃(HATI_C3)₂, superior to the reported holes-dominated MOFs.

Reference: Yang Lu, Yingying Zhang, Chi-Yuan Yang, Sergio Revuelta, Haoyuan Qi, Chuanhui Huang, Wenlong Jin, Zichao Li, Victor Vega, Yannan Liu, Xing Huang, Darius Pohl, Miroslav Polozǐj, Shengqiang Zhou, Enrique Canovas, Thomas Heine, Simone Fabiano, Xinliang Feng, Renhao Dong. Nature Communications, 2022, 13, 7240.

Acknowledgements: We acknowledge cfaed and Dresden Center for Nano- analysis (DCN) at TUD. We acknowledge the financial support from ERC starting grant (FC2DMOF, No. 852909), EU Graphene Flagship (Core3, No. 881603), ERC Consolidator Grant (T2DCP), DFG projects (CRC-1415, No. 417590517; SPP-1928, COORNET), H2020-MSCA-ITN (ULTIMATE, No. 813036), EMPIR-20FUN03-COMET, H2020-FETOPEN (PROGENY, 899205) as well as the German Science Council and Center of Advancing Electronics Dresden (cfaed). R.D. thanks Taishan Scholars Program of Shandong Province (tsqn201909047). S.F. acknowledges support from the Swedish Research Council (2020-03243) and the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU 2009-00971). Y. Z. acknowledges China Scholarship Council. Y. L. and Y. Z. acknowledge ZIH Dresden for computer time.

Highly Cited Researcher 2022

November 18, 2022

Prof. Dr. Xinliang Feng has been listed as highly cited researcher in 2022 - in the categories Chemistry and Material Science.

Dr. Minghao Yu, research group leader in Prof. Feng's group, has been listed as well as highly cited researcher in 2022 in the category Materials Science.

Dr. Renhao Dong, research group leader in Prof. Feng's group, has been listed as well as highly cited researcher in 2022 in the Cross-Field category.

Former colleagues in the group of Prof. Feng, Dr. Jian Zhang and Dr. Faxing Wang, are also among the highly cited researchers in 2022 in the Cross-Field category.

Link: Highly cited researcher 2022

Selective activation of four quasi-equivalent C–H bonds yields N-doped graphene nanoribbons with partial corannulene motifs

November 2, 2022

Selective C–H bond activation is one of the most challenging topics for organic reactions, which has been referred to as “chemistry’s ultimate prize”. Introducing heteroatoms, such as nitrogen and sulfur atoms into the organic skeleton, is an established approach to activate vicinal C atoms such as ortho C atoms. However, this strategy lacks selectivity among equivalent/quasi-equivalent ortho C atoms in heterocycles. In this regard, the step-wise, kinetic activation of equivalent/quasi-equivalent of ortho C(sp³) atoms would be a major achievement in the field. The researchers from the group of Prof. Xinliang Feng in collaboration with the group of Prof. Hong-Jun Gao and Prof. Shixuan Du (Chinese Academy of Sciences, Beijing, China) successfully achieve the selective activation of four quasi-equivalent C–H bonds in a specially designed nitrogen-containing polycyclic hydrocarbon (N-PH). Density functional theory calculations reveal that the adsorption of N-PH on Ag(100) differentiates the activity of the four ortho C(sp³) atoms in the N-heterocycles into two groups, suggesting a selective dehydrogenation, which is demonstrated by sequential-annealing experiments of N-PH/Ag(100). Further annealing leads to the formation of N-doped graphene nanoribbons with partial corannulene motifs, realized by the C–H bond activation process. This work provides a route of designing precursor molecules with ortho C(sp³) atom in an N-heterocycle to realize surface-induced selective dehydrogenation in quasi-equivalent sites.

This article featured in a Nature Communications Editors’ Highlights webpage of recent research called “Materials science and chemistry”, see https://www.nature.com/collections/wtpqpqpgwd

Reference: Yixuan Gao, Li Huang, Yun Cao, Marcus Richter, Jing Qi, Qi Zheng, Huan Yang, Ji Ma, Xiao Chang, Xiaoshuai Fu, Carlos-Andres Palma, Hongliang Lu, Yu-Yang Zhang, Zhihai Cheng, Xiao Lin, Min Ouyang, Xinliang Feng, Shixuan Du, Hong-Jun Gao. Nature Communications, 2022, 13, 6146.

Acknowledgments: We acknowledge the financial support from the National Natural Science Foundation of China (No. 61888102, 61622116 and 11974403), National Key Research and Development Program of China (No. 2018YFA0305800 and 2019YFA0308500), the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDB30000000), the German Research Foundation (DFG) with EnhanceNano (No. 391979941), the CAS Project for Young Scientists in Basic Research (YSBR-003), the CAS Frontier Sciences and Education grant (No. QYZDBSSW-SLH038), the K. C. Wong Education Foundation and the CAS Pioneer Hundred Talents Program. Z.H. Cheng was supported by the Fundamental Research Funds for the Central Universities and the Research Funds of Renmin University of China (No. 18XNLG01). Part of the research was performed in the Key Laboratory of Vacuum Physics, Chinese Academy of Sciences. Computational resources were provided by the National Supercomputing Center in Tianjin Municipality, China.

Congratulations to Adrián Romani Vazquez for successfully defending his PhD

October 17, 2022

Adrián Romani Vazquez successfully defended his PhD on "Scaling up electrochemical exfoliation: In-situ functionalization and processing of graphene materials" on October 17, 2022. Congratulations Dr. Romani Vazquez!

CGCA Young Researchers Award goes to Dr. Zhiyong Wang

October 11, 2022

This year, the CGCA Young Researchers Award goes to Dr. Zhiyong Wang. He is honoured for his excellent work in the synthesis of organic two-dimensional (2D) materials during his PhD studies at Prof. Feng’s group. Congratulations!

Zhiyong joined our research group as a PhD student in October 2017 at TU Dresden. His major academic contribution lies in the design and synthesis of 2D polymer and 2D conjugated metal-organic framework thin films based on novel on-water surface synthesis strategies. After graduation, he was appointed as a research group leader at TU Dresden and Max Planck Institute of Microstructure Physics, being responsible for the 2D polymer and interfacial synthesis group.

Congratulations to Jinjiang Zhang for successfully defending his PhD

September 30, 2022

Jinjiang Zhang successfully defended his PhD on "Bottom-up Synthesis of Boron-Doped Polycyclic Aromatic Hydrocarbons and Graphene Nanoribbons" on September 30, 2022. Congratulations Dr. Zhang!

CSC-Award granted to M.S. Jinjiang Zhang

September 6, 2022

Jinjiang Zhang, PhD student in the Chair of Molecular Functional Materials at TU Dresden, was selected to receive the "2021 Chinese Government Award for Outstanding Self-financed Students Abroad" by the China Scholarship Council. Congratulations!

M.S Jinjiang Zhang joined Prof. Xinliang Feng’s group at TU Dresden as a PhD student from August 2018. His PhD study focused on the “Bottom up synthesis of boron-doped polycyclic aromatic hydrocarbons and graphene nanoribbons”. This award recognizes his work during his PhD studies at Prof. Feng’s group.

The Chinese Government Award for Outstanding Self-financed Students Abroad was established by the China Scholarship Council in 2003 and aims at rewarding the academic excellence of self-financed Chinese students studying overseas. It is considered to be the highest award given by the Chinese government to graduate students studying aboard. Only those with outstanding performance in their PhD studies will be considered by the award panel and no more than 500 young talents will be granted the award each year all over the world.

WP13 Progress Meeting at TU Dresden

May 13, 2022

On April 25^th & 26^th, 2022, the Progress Meeting of the Working Package of Environmental Foams and Coatings of the Graphene Flagship project took place at TU Dresden. The meeting was organized by Prof. Xinliang Feng and Dr. Ali Shaygan Nia from the Chair for Molecular Functional Materials.

In this meeting, different EU partners from academia and industry share their latest developments on environmental applications of Two-Dimensional (2D) Materials like Water/Air Purification, Anticorrosion Coating, and Health Monitoring Devices.

HYSUCAP Progress Meeting at TU Dresden

May 13, 2022

On April 11, 2022, the HYSUCAP Progress Meeting took place on-site at TU Dresden, organized by Dr. Minghao Yu from the chair for Molecular Functional Materials.

The HYSUCAP project is funded under the network of M-ERA.NET 2, and explores the development of novel 2D hybrids based on MXenes and black phosphorus for advanced supercapacitors. The purpose of the progress meeting was to exchange the collaborative achievement of three international partners, namely teams from TU Dresden, TU Brno, and University of Warsaw. The team members also discussed the future strategies regarding the project activities.

Prof. Hongjie Dai has been awarded the prestigious Humboldt research prize

May 5, 2022

Prof. Hongjie Dai is an international authority in the field of materials chemistry, physics and nanoscience. His pioneering work has promoted basic research in chemistry and physics of quasi-1D carbon nanomaterials. He has made a great contribution to the development of single-wall carbon nanotubes, graphene nanoribbons, renewable energy storage, and nanomedicine. During his stay in Germany, he continues his research on carbon-based materials for electrocatalysis, batteries and nanomedicine.

Professor Dai is hosted by Prof. Xinliang Feng at the Dresden University of Technology and Max Planck Institute of Microstructure Physics.

The Humboldt research prize is awarded annually to up to 100 internationally renowned scientists worldwide for their outstanding research and lifetime achievements. For more information go to: https://www.humboldt-foundation.de/bewerben/foerderprogramme/humboldt-forschungspreis

Prof. Donglin Jiang has been awarded the prestigious Humboldt research prize

May 5, 2022

Professor Donglin Jiang is internationally recognized for his outstanding research in polymer materials. He has made significant contributions to the development of covalent organic frameworks. Prof. Jiang has developed various design principles and synthetic strategies for covalent organic frameworks, which provide a fundamental material platform for exploring unique properties and functional applications. During his stay in Germany, he intends to elaborate the important parameters that control the crystal formation in both bulk powders and thin films of covalent organic frameworks and 2D polymers, as well as the underlying physical properties involving photons, electrons and spins.

Professor Jiang is hosted by Prof. Xinliang Feng and Prof. Thomas Heine at the Dresden University of Technology.

The Humboldt research prize is awarded annually to up to 100 internationally renowned scientists worldwide for their outstanding research and lifetime achievements. For more information go to: https://www.humboldt-foundation.de/bewerben/foerderprogramme/humboldt-forschungspreis

CRC 1415 Guest Lecture Prof. Andrey Turchanin

April 28, 2022

The consortium of the Collaborative Research Center (CRC) 1415 would like to thank Prof. Dr. Andrey Turchanin, Friedrich-Schiller-Universität Jena, for his guest lecture on 28^th Ap-ril 2022. In his scientific talk "Heterostructures of Organic & Inorganic 2D Materials: Engineering & Device Applications" Prof. Andrey Turchanin reported on the recent progress in the synthesis, characterization, engineering, and device applications of heterostructures composed of various 2D materials such as graphene, transition metal dichalcogenides, and molecular nanosheets.

CRC 1415 Guest Lecture Prof. Francesco Bonaccorso

March 24, 2022

The consortium of the CRC 1415 is pleased to invite Prof. Dr. Francesco Bonaccorso, Institute Italiano di Tecnologia, Italy, for the CRC seminar talk on March 24, 2022. Within the frame of his virtual presentation “Large-Scale Production of 2D Crystals for Energy Applications“, he discussed the key properties of graphene and related two-dimensional materials (GRMs) and he presented the strategy of BeDimensional in the production of GRMs by wet-jet milling and the industrial scale up. Moreover, he provided a brief overview on some key applications of the as-produced GRMs, for anticorrosion coatings and energy conversion and storage devices.

CRC 1415 Guest Lecture Prof. Mischa Bonn

February 17, 2022

The CRC consortium is delighted to welcome Prof. Mischa Bonn and guests at the Technische Universität Dresden. Prof. Mischa Bonn, Max-Planck-Institut für Polymerforschung, reported in his scientific talk "Optical Characterization of Electro-Optic Materials (Synthesis)" on the synthesis of novel 2D materials at the water surface and the factors determining the crystallinity of the resulting product. Moreover, Prof. Bonn demonstrated how non-invasive optical methods can provide fundamental insights into new materials and their synthesis.

Congratulations to Dominik Pastötter for successfully defending his PhD

February 11, 2021

Dominik Pastötter successfully defended his PhD on "Synthesis of Vinylene-Linked Two-Dimensional Conjugated Polymers" on February 10, 2022. Congratulations Dr. Pastötter!

CRC 1415 Guest Lecture Prof. Petko Petkov

January 27, 2022

The CRC 1415’s consortium was pleased to invite Prof. Petko Petkov, University of Sofia, for the CRC seminar talk on January 27, 2022. Within the frame of his presentation on “Electronic Properties of 2D Conjugated Metal-Organic Frameworks Based on Phthalocynine fragments“, he explained in a vivid manner that metal-organic frameworks (MOFs) offer an attractive platform for addressing charge conductivity, which may enable them to become active elements in optoelectronic devices.

CRC 1415 Guest Lecture Prof. Ron Naaman

January 24, 2022

The CRC 1415’s consortium was pleased to invite Prof. Ron Naaman, Weizmann Institute, Rehovot, Israel, for the CRC seminar talk on January 20, 2022. Within the frame of his presentation “Chiral Material and the Electrons’ Spin – A Miraculous Match“, he explained that chiral molecules, crystals and films act as spin filters for photoelectrons transmission, in electron transfer, and in electron transport.

Virtual Workshop "Advances in Precision Carbon Nanostructures" in honor of Prof. Klaus Müllen's 75th Birthday

January 21, 2021

Virtual Workshop Attracts 300 Attendees Worldwide

On January 20th and 21st, 2022 about 300 researchers from all over the world gathered online to participate in our virtual workshop on Advances in Precision Carbon Nanostructures. Four sections gave sufficient room to approach the topic from various sides. A total of 20 invited speakers, coming from research institutions in Germany, China, the United Kingdom, France, Japan, and Switzerland, reported about the latest developments in their fields - discussing such issues like applicability, synthesis, nanoscience, precision, and non-natural materials.

But the aim of this workshop was also to celebrate the contributions of Prof. Klaus Müllen to this field. His ground-breaking research, for example, paved the way for synthetic light-emitting organic materials, such as OLEDs.

Most of the speakers have been long-time collaborators of Prof. Müllen and expanded his research into new directions or even new fields. To name a few from the workshop agenda:

• Sonopharmacology: How to active drugs by ultrasound
• Precisely controlled self-organization of molecular carbon nanostructures
• Nanodiamonds – From synthesis to quantum sensing in biology
• On-surface synthesis of atomically precise carbon nanostructures

Hence, this workshop could also be called a gathering of the “Müllen family,” to quote the guest of honor.

In his summary, Prof. Müllen pointed out the ongoing importance of fundamental research, the need for an open mind when material scientists rooted in chemistry define their synthetic toolbox, and the chances his field offers to provide solutions for major societal needs. Finally, he also encouraged the audience to “employ concepts of artificial intelligence which will help us to fill gaps of knowledge of materials science much faster and more comprehensively than by performing one experiment after the other.”

The meeting was organized by Prof. Xinliang Feng, TU Dresden and MPI of Microstructure Physics, Halle, and Dr. Ji Ma, TU Dresden. Both Prof. Müllen and Prof. Feng received in 2017 the Hamburg Science Award for their ground-breaking work on graphene nanostructures.

Congratulations to Huanhuan Shi for successfully defending her PhD

January 10, 2021

Huanhuan Shi successfully defended her PhD on "Exfoliation and Functionalization of Emerging 2D Semiconductors via Wet Chemistry” on January 10, 2022. Congratulations Dr. Shi!

Innovation Group wins the 1^st place award of the Helmholtz-Zentrum Dresden-Rossendorf Innovation Contest 2021

December 17, 2021

Payam Hashemi (on behalf of the Innovation Group of the Chair of Molecular Functional Material, cfaed), Carolin Heller (University Hospital Dresden) and Ehsan Mohseni (Institute of Fluid Dynamics, HZDR), as an interdisciplinary research team, won the 1^st place award of the Helmholtz-Zentrum Dresden-Rossendorf Innovation Contest 2021 for a self-regulated electronic bioimplant device that recognises an important malfunction in the body and automatically corrects it.

Dr. Minghao Yu receives the EnSM Young Scientist Award 2021

December 16, 2021

Dr. Minghao Yu was announced as one of three winners of the Energy Storage Materials (EnSM) Young Scientist Award 2021. Congratulations. The purpose of the EnSM Young Scientist Award is to recognize three very promising young scientists (less than 40 years old) in the field of energy storage materials and devices who have shown great potential from their work with significant innovation in the field. The winners are invited to write a paper for the journal Energy Storage Materials, and to join the Editorial Board of the journal. The award EnSM Young Scientist Award includes a certificate and an award of 500 USD.

Boosting the Electrocatalytic Conversion of Nitrogen to Ammonia on Metal-Phthalocyanine-Based Two-Dimensional Conjugated Covalent Organic Frameworks

December 13, 2021

Electrochemical nitrogen reduction reaction (NRR), particularly in conjunction with renewable energy, is regarded as a promising and sustainable alternative to the current high temperature/pressure Harber-Bosch process for the production of ammonia under ambient conditions. The current electrochemical NRR process suffers from extremely sluggish kinetics and low selectivity due to the high energy barriers of N₂ activation and the faster kinetics of the competing hydrogen evolution reaction (HER) in the similar potential ranges, respectively. Thus, extensive efforts have been devoted to explore highly active and selective electrocatalysts for boosting NRR. Thereinto, heterogeneous metal-heteroatom-doped carbon-rich electrocatalyst represents one attractive alternative because of its high durability and recyclability, as well as its ease of integration into the electrode. Nevertheless, the inhomogeneity and ambiguity of the catalytic structure of metal-nitrogen-doped carbon posed major challenges in synergistically improving their activity and selectivity toward high NRR efficiency. Moreover, their inherently less defined catalytic environment hinders the fundamental studies on the reaction mechanism.

In order to address these challenges, researchers from Technical University of Dresden (Chair for Molecular Functional Materials) and collaborators have presented the first case of two-dimensional conjugated covalent organic frameworks (2D c-COFs) incorporated with M-N₄-C centers as sufficient catalysts, achieving simultaneously enhanced activity and selectivity of electrocatalytic NRR to ammonia. Such 2D c-COFs are synthesized based on metal-phthalocyanine (M = Fe, Co, Ni, Mn, Zn and Cu) and pyrene units bonded by pyrazine linkages. The 2D c-COFs with Fe-N₄-C center exhibit higher ammonia yield rate (33.6 mg h^-1mg^-1_cat) and Faradaic efficiency (FE, 31.9 %) at -0.1 V vs. reversible hydrogen electrode than those with other M-N₄-C centers, making them among the best NRR electrocatalysts (yield rate >30 mg h^-1mg^-1_cat and FE >30 %). In-situ X-ray absorption spectroscopy, Raman spectroelectrochemistry and theoretical calculations unveil that Fe-N₄-C centers act as catalytic sites. They show unique electronic structure with localized electronic states at Fermi level, allowing for the stronger interaction with N₂, thus faster N₂ activation and NRR kinetics than other M-N₄-C centers. Our work opens the possibility of developing metal-nitrogen-doped carbon-rich 2D c-COFs as superior NRR electrocatalyst and provides an atomic understanding of NRR process on M-N_x-C based electrocatalysts for designing high-performance NRR catalysts

Reference: Haixia Zhong, Mingchao Wang, Mahdi Ghorbani-Asl, Jichao Zhang, Khoa Hoang Ly, Zhongquan Liao, Guangbo Chen, Yidan Wei, Bishnu P. Biswal, Ehrenfried Zschech, Inez M. Weidinger, Arkady V. Krasheninnikov, Renhao Dong,and Xinliang Feng. Boosting the Electrocatalytic Conversion of Nitrogen to Ammonia on Metal-Phthalocyanine-Based Two-Dimensional Conjugated Covalent Organic Frameworks. J. Am. Chem. Soc. 2021, 143, 47, 19992–20000.

This work is financially supported by EU Graphene Flagship (GrapheneCore3, No. 881603), ERC starting grant (FC2DMOF, No. 852909), ERC Consolidator Grant (T2DCP), Coordination Networks: Building Blocks for Functional Systems (SPP 1928, COORNETs), and CRC 1415 (Chemistry of Synthetic Two-Dimensional Materials, No. 417590517), as well as the German Science Council and Center for Advancing Electronics Dresden (cfaed). R.D. thanks Taishan Scholars Program of Shandong Province (tsqn201909047). H.Z. gratefully acknowledges funding from the Alexander von Humboldt Foundation. I.M.W. acknowledges the Cluster of Excellence UniSysCat (EXC 2008/1-390540038). We acknowledge Dresden Center for Nanoanalysis (DCN) at TUD and Dr. Petr Formanek (Leibniz Institute for Polymer Research, IPF, Dresden) for the use of facilities. We thank the scientists at beamline BL14W1 and BL15U1 of the Shanghai Synchrotron Radiation Facility for the XAFS measurements. We appreciate Prof. Thomas Heine and Hung-Hsuan Lin for providing the structural model. We also appreciate Na Zhou for IC measurement from Changchun institute of applied chemistry (CIAC). We thank Prof. Xiaodong Zhuang for the in-situ XAS electrochemical cell setup. The computational support from the HZDR computing cluster, Technical University of Dresden cluster (TAURUS), High Performance Computing Center (HLRS) in Stuttgart, Germany, and CSC Finland, is gratefully appreciated.

Prof. Xinliang Feng elected as new acatech Member

December 9, 2021

Prof. Xinliang Feng was elected as a new Member of Germany's National Academy of Science and Engineering (acatech) on October 19, 2021. The election is an award for outstanding achievements in science and technology and at the same time an honorary mandate: acatech advises policymakers and society on strategic engineering and technology policy issues.

As the national academy and voice of the engineering sciences in Germany and abroad, acatech brings together more than 600 personalities from science and industry. Members from the fields of engineering and natural sciences, medicine, the humanities and social sciences are admitted to the academy on the basis of their scientific achievements and reputation.

Members deal with topics such as biotechnology, energy and resources, healthcare technologies, or mobility. Positions, studies, discussions and other writings on socially and economically relevant topics are published. The results are made available to politicians, industry and interested members of the public.

Link: https://en.acatech.de/person/xinliang-feng-technische-universitat-dresden

On-water surface synthesis of charged 2D polymer single crystals via the irreversible Katritzky reaction

December 7, 2021

The exploration of kinetically irreversible bond formation for the synthesis of two-dimensional polymers (2DPs) and their layer-stacked 2D covalent organic frameworks (2D COFs) has remained scarce, mostly due to the incomplete reactions or polymorphism, as well as the lack of error-correction. By far, only the recent achievements using Knoevenagel (Polym. Chem. 7, 4176-4181 (2016), Science 357, 673-676 (2017)), Aldol-type (J. Am. Chem. Soc. 141, 6848-6852 (2019)) and Horner-Wadsworth-Emmons condensation reactions (Angew. Chem. Int. Ed. 59, 23620-23625 (2020)) have demonstrated the possibility of synthesizing crystalline 2D COFs from solution syntheses. To access single-layer 2DPs via aryl-aryl coupling, the on-surface assisted Ullmann-type coupling under ultrahigh vacuum conditions has received much attention in the last decade (Nat. Chem. 9, 563-570 (2017), Nat. Mater. 19, 874-880 (2020)). Nevertheless, these approaches have remained limited to making microcrystalline products with domain sizes up to dozens of nanometers. Therefore, the synthesis of single-crystalline 2DPs and 2D COFs via irreversible reactions constitutes an immense challenge.

Figure (a) Structure of C2DP with a square lattice (a = b = 30.5 Å). Inset, Optical microscopy image of C2DP film. (b) Aberration Corrected High-Resolution Transmission Electron Microscopy (AC-HRTEM) image of C2DP acquired with a total electron dose of 70 e^- Å^-2. (c) C2DP-based osmotic power generation under salinity gradient.

The researchers from Prof. Xinliang Feng and Dr. Renhao Dong’s group recently reported the synthesis of few-layer, large-area, single-crystalline cationic 2DPs (C2DPs) through an irreversible Katritzky reaction on the water surface. Probing the interfacial ring-transmutation polymerization mechanism by theoretical calculation and model reaction, unveils that manipulating pH in ring opening and ring closure steps controls the reaction kinetics toward the C2DP structures. As a consequence, the researchers demonstrate the synthesis of C2DP single crystals by irreversible reactions under kinetic control. Representatively, the C2DP single crystals display a tunable thickness of ~ 2-30 nm, and a lateral size up to 120 µm², which is far beyond the thus-far reported 2DPs and 2D COFs synthesized by the irreversible bonds. The crystal structure with the atomic precision is resolved by imaging and diffraction methods, revealing a highly uniform square-patterned structure with the in-plane lattice of a = b = 30.5 Å. The positively-charged framework is counterbalanced by BF₄^- ions and is characterized by spectroscopy and single-crystal analysis of a representative example.

Significantly, the C2DP crystals with cationic polymer skeleton and columnar-like pore arrays offer a high chloride ion selectivity with a coefficient up to 0.9, thus ensuring the integration as the anion-selective membrane for the osmotic energy generation. As a result, an output power density as high as 4.0 W m^-2 is achieved which outperforms the state-of-art 2D materials such as graphene and boron nitride. These achievements reveal a route for synthesizing 2DP and 2D COF single crystals using a kinetically-controlled irreversible reaction, and will spark further efforts to rationally design crystalline 2DPs with charged backbones towards osmotic power generation.

Reference: Zhiyong Wang, Zhen Zhang, Haoyuan Qi, Andres Ortega-Guerrero, Lihuan Wang, Kun Xu, Mingchao Wang, SangWook Park, Felix Hennersdorf, Arezoo Dianat, Alexander Croy, Hartmut Komber, Gianaurelio Cuniberti, Jan J. Weigand, Ute Kaiser, Renhao Dong, and Xinliang Feng, On-water surface synthesis of charged two-dimensional polymer single crystals via the irreversible Katritzky reaction, Nature Synthesis, 2022, DOI: 10.1038/s44160-021-00001-4.

https://www.nature.com/articles/s44160-021-00001-4

Acknowledgments: This work is financially supported by EU Graphene Flagship (GrapheneCore3, No. 881603), ERC starting grant (FC2DMOF, No. 852909), ERC Consolidator Grant (T2DCP), DFG project (2D polyanilines, No. 426572620), Coordination Networks: Building Blocks for Functional Systems (SPP 1928, COORNET), H2020-MSCA-ITN (ULTIMATE, No. 813036), H2020-FETOPEN (PROGENY, 899205), CRC 1415 (Chemistry of Synthetic Two-Dimensional Materials, No. 417590517), SPP 2244 (2DMP), as well as the German Science Council and Center of Advancing Electronics Dresden. Z. W. gratefully acknowledges funding from China Scholarship Council. The authors acknowledge Center of Advancing Electronics Dresden and Dresden Center for Nanoanalysis at TUD and Dr. Petr Formanek, Prof. Andreas Fery for the use of TEM facility at IPF.

Virtual Workshop on Advances in Precision Carbon Nanostructures on January 20 - 21, 2022 / Celebration of the 75th Birthday of Prof. Dr. Klaus Müllen

December 6, 2021

The chair of Prof. Xinliang Feng at TU Dresden is organizing a virtual workshop on Advances in Precision Carbon Nanostructures from January 20 - 21, 2022. The workshop is being organized to celebrate the 75th Birthday of Prof. Dr. Klaus Müllen.

For further information go to: Workshop Announcement.

Congratulations to Xia Wang for successfully defending her PhD

December 4, 2021

Xia Wang successfully defended her PhD on "Developing Advanced Oxygen Electrocatalysts for Zinc-Air Batteries: from Morphology Control to Electronic Structure Manipulation” on December 2, 2021. Congratulations Dr. Wang!

Dr. Jinxin Liu received the prestigious Humboldt Research Fellowship for Postdoctoral Researchers

December 4, 2021

The Humboldt Research Fellowship is awarded to researchers from abroad with above average qualifications and who are at the beginning of their career. By being granted this fellowship, Dr. Jinxin Liu, will receive financial support for two years to carry out his research in the research group of Prof. Xinliang Feng and Dr. Renhao Dong at Technische Universität Dresden.

2021 USERN Prize awarded to Dr. Minghao Yu at USERN Congress in Istanbul

December 3, 2021

Congratulations to Dr. Minghao Yu for the honor to be selected as the 2021 USERN Laureate in the field of physical and chemical sciences for his outstanding and innovative research ‘Developing sustainable energy storage devices with resource-abundant raw materials’.

Purposing on acknowledging junior scientists for all their efforts and achievements and encouraging them to proceed with their goals, the Universal Scientific Education and Research Network (USERN) was established in 2015. The USERN Prize is awarded to junior scientists and researchers less than 40 years of age who has conducted novel research, educational, or humanity service program or proposed a novel theory proceeded with a scientific approach. Over 10,000 eligible candidates have been nominated for USERN Prize 2021 in 5 major fields of science: Formal Sciences, Physical and Chemical Sciences, Biological Sciences, Medical Sciences, and Social Sciences. The applications have been carefully reviewed and scored by more than 100 top 1% well-known scientists. Finally, five USERN Laureates have been selected. The USERN Award includes USERN Prize Statuette, USERN Medal, 2,000 USD cash award, up to 1,000 USD Travel Grant, an honorary advisory board of USERN for 3 years, and 2,000 USD USERN Grant for the establishment of an active interest group in USERN. The prize-awarding festival took place on November 10, 2021, in Istanbul, Turkey.

A special collection on 2D Congratulations to Zhiyong Wang for successfully defending his PhD

November 30, 2021

The guest editors Dan Zhao and Xinliang Feng provided a brief overview of the field and highlight the state-of-the-art contributions featured in this special collection. The field of 2D materials and their applications has exploded since 2004, when graphene was successfully prepared by Geim, Novoselov and co-workers.¹ In the subsequent decade-and-a-half, the scientific community has shown great enthusiasm for studying graphene and graphene-analogous 2D materials, including the transition metal dichalcogenides (TMDs), graphitic carbon nitride (g-C₃N₄), hexagonal boron nitride (h-BN), black phosphorus (BP), MXenes, silicene, etc.² Very recently, organic 2D crystalline materials such as single- to few-layer 2D metal-organic frameworks (MOFs)³, 2D polymers⁴ and 2D covalent organic frameworks (COFs)⁵ with large surface areas, diverse functionalities, and high chemical stabilities have been regarded as an emerging member of the family of 2D materials. The availability of these 2D materials has also experienced an impressive growth over the past decade that finds a prolific manifestation in numerous applications, including sensors, opto-electronics, chemical separations, drug-delivery systems, and other energy and environmentally related applications.

Guest editors Prof. Dan Zhao and Prof. Xinliang Feng @Chemistry-An Asian Journal

Despite the exciting achievements in the field of 2D materials and their applications, challenges still exist. The studies on emerging 2D materials and their van der Waals layer-stacked structures such as graphdiyne, 2D MOFs, 2D COFs, and their applications are still in the infant stage. Large-scale production of 2D materials with high quality and controlled structures has yet to be realized for ultimate industrialization. Furthermore, the precise manipulation of thicknesses, functionalities, topologies, crystal phases, and lateral sizes of 2D materials is still challenging. Commercializing 2D materials will be a major milestone, and we still need to contribute ongoing efforts to achieve this goal. Targeting at these goals, here, we are greatly honored to assemble a compendium of the latest studies on 2D materials and their applications, covering a wide array of topics.

The articles selected in this collection have a multidisciplinary nature and include contributions of more than twenty research groups, whose research ranges from the design, synthesis, and characterization of advanced 2D materials to their applications in various directions. Eight Minireviews present overviews on 2D graphdiyne, 2D MOFs, 2D COFs, silicate materials, and g-C₃N₄ in fascinating applications, including electrochemistry, electromagnetic shielding/absorbing, catalysis, supercapacitors, sensors, gas adsorption/separation, water pollution removal, energy conversion, and electrochromic switching. One Communication and twelve Full Papers report new research results on synthesizing advanced 2D MOFs, COFs, layered double hydroxides, MXenes, perovskites, and graphene oxide materials for membrane separations, adsorption, electrocatalysis, sodium-ion batteries, etc.

In summary, this special collection aims to provide the recent state-of-the-art progress in 2D materials and their applications. We strongly believe that the compilation of these excellent review and research articles covering broad topics related to 2D materials and their applications could benefit researchers in diverse fields. We hope this collection could provide the readers with some representative and exciting views regarding the new developments and applications of 2D materials. Toward this end, we would like to express our sincere gratitude toward the authors and the editorial staff for their great contributions to this special collection.

Reference: [1] K. S. Novoselov, A. K. Geim, S. V. Morozov, D. Jiang, Y. Zhang, S. V.Dubonos, I. V. Grigorieva, A. A. Firsov, Science 2004, 306, 666–669. [2] H. Zhang, Chem. Rev. 2018, 118, 6089–6090. [3] M. T. Zhao, Y. Huang, Y. W. Peng, Z. Q. Huang, Q. L. Ma, H. Zhang, Chem. Soc. Rev. 2018, 47, 6267–6295. [4] K. J. Liu, H. Y. Qi, R. H. Dong, R. Shivhare, M. Addicoat, T. Zhang, H. Sahabudeen, T. Heine, S. Mannsfeld, U. Kaiser, Z. K. Zheng, X. L. Feng, Nat. Chem. 2019, 11, 994–1000. [5] D. Rodriguez-San-Miguel, C. Montoro, F. Zamora, Chem. Soc. Rev. 2020, 49, 2291–2302.  doi.org/10.1002/asia.202101283

Congratulations to Zhiyong Wang for successfully defending his PhD

November 26, 2021

Zhiyong Wang successfully defended his PhD on “On-Water Surface Synthesis of Two-Dimensional Organic Framework Films Enabling Effective Ion/Charge Transport” on November 25, 2021. Congratulations Dr. Wang!

Highly Cited Researcher 2021

November 23, 2021

Prof. Dr. Xinliang Feng has been listed as highly cited researcher in 2021 - in the categories Chemistry and Material Science.

Dr. Minghao Yu, research group leader in Prof. Feng's group, has been listed as well as highly cited researcher in 2021 in the category Materials Science.

Former colleagues in the group of Prof. Feng, Dr. Yang Hou and Dr. Xiaodong Zhuang, are also among the highly cited researchers in 2021 in the Cross-Field category.

https://recognition.webofscience.com/awards/highly-cited/2021/

Renhao Dong has been invited to become a member of the Young Academy of Europe (YAE)

November 8, 2021

The Board of the Young Academy of Europe (YAE) has unanimously agreed to invite Dr. Renhao Dong to become a member.

The YAE is a pan-European initiative which supports outstanding young scientists and scholars in regards to e.g. networking and scientific exchange. Since 2019 it is a registered charity organization.

Fore more information go to: https://yacadeuro.org/

Chemist Lei Fang from Texax A&M University received the Humboldt Research Fellowship and plans to visit TU Dresden in 2022

October 27, 2021

Associate Professor Lei Fang from Texax A&M University received the prestigious Humboldt Research Fellowship for Experienced Researchers in support of his research on conjugated polymers and novel organic materials with unprecedented electronic or optical properties and application.

Lei Fang plans to visit TU Dresden and the chair of Prof. Dr. Xinliang Feng in February 2022. During his visit he will collaborate with Prof. Feng and his group on the synthesis and application of graphene nanoribbons and porous graphitic carbon.

Fore more information on Lei Fang and his Humboldt Research Fellowship, go to https://science.tamu.edu/news/2021/05/texas-am-chemist-lei-fang-honored-with-humboldt-research-fellowship/.

Viologen-Immobilized 2D Polymer Film Enabling Highly Efficient Electrochromic Device for Solar-Powered Smart Window

October 27, 2021

Two-dimensional polymers (2DPs) and their layer-stacked 2D covalent organic frameworks (2D COFs) are an emerging class of organic layered materials with well-defined permanent porosity. Thanks to their tailor-made structures and properties, these porous crystalline polymers have exhibited the potential for broad functions in optoelectronics, membrane, catalysis, and energy storage and conversion. Recent advances have demonstrated that 2D COFs integrated with color-switching, redox-active units such as triphenylamine in the backbones could present reversible color switching and are, therefore, excellent candidates for electrochromic devices (ECDs). Nevertheless, these 2D COF-based ECDs have not unleashed their full potential to display high coloration efficiency (CE) (while few examples could reach over 800 cm² C⁻¹) due to the random stacking of crystallites and the presence of amorphous defects that lead to restricted ion diffusion. In this regard, achieving related materials with highly ordered and oriented columnar-like pores could provide a large interface area with the electrolyte, high utilization of built-in color-switching components, and fast ion diffusion, which are crucial for realizing a quick and efficient EC switching.

The researchers from Prof. Xinliang Feng’s group recently demonstrated the high-performance ECDs with a fully crystalline viologen-immobilized 2D polymer (V2DP) thin film as the color-switching layer. The high density of vertically oriented pore channels (pore size ≈ 4.5 nm; pore density ≈ 5.8 × 10¹⁶ m^-2) in the synthetic V2DP film enables high utilization of redox-active viologen moieties and benefits for Li⁺ ion diffusion/transport. As a result, the as-fabricated ECDs achieve a rapid switching speed (coloration, 2.8 s; bleaching, 1.2 s), and a high CE (989 cm² C^-1), and low energy consumption (21.1 µW cm^-2). Moreover, it is managed to fabricate transmission-tunable, self-sustainable EC window prototypes by vertically integrating the V2DP ECDs with transparent solar cells. This work sheds light on designing electroactive 2D polymers with molecular precision for optoelectronics and paves a practical route toward developing self-powered EC windows to offset the electricity consumption of buildings.

Reference: Zhiyong Wang, Xiangkun Jia, Panpan Zhang, Yannan Liu, Haoyuan Qi, Peng Zhang, Ute Kaiser, Sebastian Reineke, Renhao Dong, Xinliang Feng, Viologen-Immobilized 2D Polymer Film Enabling Highly Efficient Electrochromic Device for Solar-Powered Smart Window, Adv. Mater. 2021, 2106073. https://doi.org/10.1002/adma.202106073

Acknowledgments: This work was financially supported by EU Graphene Flagship (GrapheneCore3, No. 881603), ERC starting grant (FC2DMOF, No. 852909), ERC Consolidator Grant (T2DCP), Coordination Networks: Building Blocks for Functional Systems (SPP 1928, COORNET), H2020-MSCA-ITN (ULTIMATE, No. 813036), H2020-FETOPEN (PROGENY, 899205), CRC 1415 (Chemistry of Synthetic Two-Dimensional Materials, No. 417590517), as well as the German Science Council and Center of Advancing Electronics Dresden (cfaed). R.D. thanks Taishan Scholars Program of Shandong Province (tsqn201909047). Z.W. and X.J. gratefully acknowledge funding from China Scholarship Council. The authors acknowledge the Centre for High Performance Computing (ZIH) in Dresden, Germany, and the support of computational calculation from Chenghao Liu in Mcgill University, Canada.

A Modular Cascade Synthetic Strategy Toward Structurally Constrained Boron-doped Polycyclic Aromatic Hydrocarbons

October 15, 2021

Boron incorporation has attracted great interest in the last decade due to its excellent ability to modify the optoelectronic properties of PAHs, e.g., to provide the resulting systems with intense luminescence, high electron deficiency, strong Lewis acidity, and bestowing the resultant compounds with unique supramolecular behavior. Compared with the benchtop-stable boron doped PAHs (B-PAHs) obtained by applying electronic/kinetic stabilization approach, structurally constrained B-PAHs (sc-B-PAHs) stabilized by chelating effect are expected to enable tight intermolecular packing and enhance the intermolecular interaction in the solid state, therefore improving the charge carrier transport properties. Moreover, sc-B-PAHs are capable of forming Lewis acid-base complexes which can undergo photodissociation in the excited state, giving a dual fluorescence emission. Nevertheless, the related studies on sc-B-PAHs are relatively rare due to the limited synthetic approaches.

The researchers from the group of Prof. Xinliang Feng recently developed a novel synthetic strategy for the construction of difficult-to-access sc-B-PAHs via a cascade reaction from the readily available ortho-aryl-substituted diarylalkynes. This domino process features simplicity and a broad substrate scope. Not only sc-B-PAHs with B-doped [4]helicene structure but also specific BN-doped [4]helicene/double-[4]helicene can be constructed by this approach. Noteworthily, the resultant BN-doped [4]helicene demonstrate distinct supramolecular behavior in the solid state, e.g. mono [4]helicene 1o forms a unique π-stacked dimer and adopts helical columnar stacking, while double [4]helicene 1u establishes an unprecedented π-stacked trimeric structure with a 2D lamellar π-stacking. The presented strategy thus provides a new pathway for the development of novel sc-B-PAHs and expanded B-doped graphene nanostructures.

Reference: Jin-Jiang Zhang, Lin Yang, Fupin Liu, Yubin Fu, Junzhi Liu, Alexey A. Popov, Ji Ma, Xinliang Feng. A Modular Cascade Synthetic Strategy Toward Structurally Constrained Boron-doped Polycyclic Aromatic Hydrocarbons. Angew. Chem. Int. Ed. 2021, https://onlinelibrary.wiley.com/doi/10.1002/anie.202109840.

Acknowledgments: This research was financially supported by the EU Graphene Flagship (Graphene Core 3, 881603), ERC Consolidator Grant (T2DCP, 819698), the Center for Advancing Electronics Dresden (cfaed) and DFG-NSFC Joint Sino-German Research Project (EnhanceNano, No. 391979941), as well as the DFG-SNSF Joint Switzerland-German Research Project (EnhanTopo, No. 429265950). The authors acknowledge the use of computational facilities at the Center for information services and high performance computing (ZIH) at TU Dresden. Diffraction data have been collected on BL14.2 at the BESSY II electron storage ring operated by the Helmholtz-Zentrum Berlin, we thank Dr. Manfred Weiss and his team for assistance during the experiment.

New modular research building handed over to TUD and users

October 14, 2021

It consists of 33 prefabricated room cells and was realized by the TU Dresden on its own in only ten months of construction time: the new modular research building on Stadtgutstraße 59. On 1,200 square meters, about 45 researchers of the professorship for Molecular Functional Materials of Xinliang Feng, which is integrated in the Center for Advancing Electronics Dresden (cfaed), as well as of the Cluster of Excellence Complexity and Topology in Quantum Matter (ct. qmat) have perfect conditions for their research on the materials of the future, which ranges from 2-dimensional layered compounds with atomic thickness to materials with topological quantum phenomena. The ceremonial handover of this innovative high-tech building to its users has now taken place on October 14, 2021.

@TU Dresden/Eric Münch

At the ceremonial handover of the building, Science Minister Sebastian Gemkow said: "The speed of the construction work, as well as the modular and flexible design, fits perfectly with the vigorous development of research activities at TU Dresden. In recent years, we have succeeded in attracting a large number of highly ambitious research projects, to which we had to respond promptly with more space and optimal working conditions. I congratulate you today on this successful modular building, which, with its modern and reduced exterior, can serve as a benchmark for future research buildings."

@TU Dresden/Eric Münch

"With this first building project of our own, we have broken new ground. We have created a research building here that gives us the flexibility we need to strengthen research and teaching in the long term and has proven to be a time-efficient and cost-effective alternative to government construction. The idea behind this in-house construction measure was that we have reserves of research space that can then be accessed very quickly when needed," explains the Rector of TU Dresden, Prof. Ursula M. Staudinger. "This is because the pace of growth of our research groups based on their great success with third-party funding is usually far ahead of the construction of such research space and therefore presents the university with very great challenges. We would like to thank everyone who contributed to the successful implementation of this first construction measure of the TU Dresden as a building owner - an example that points the way for the future!"

Observation of fractional edge excitations in nanographene spin chains

October 13, 2021

Recently, researchers from the group of Prof. Xinliang Feng (TU Dresden, MPI Halle, Germany) in collaboration with the scientists from Switzerland, Portugal and Spain have succeeded in building carbon-based quantum spin chains, where they captured the emergence of one of the cornerstone models of quantum magnetism first proposed by the 2016 Nobel laureate F. D. M. Haldane in 1983. Published in the journal Nature, the results could have widespread implications in the understanding of low-dimensional quantum magnetism and may contribute toward the emerging field of quantum computation.

We are all used to the idea that simpler units in nature interact to form complex structures. Take for example the hierarchy of life, where atoms combine to form molecules, molecules combine to form cells, cells combine to form tissues, and so on, ultimately leading to the formation of complex organisms such as humans. However, in the quantum world this process may play in reverse, where interactions between two complex objects leads to the emergence of simpler species.

Picture: Artistic rendering of a triangulene quantum spin chain adsorbed on a gold surface and probed with the sharp tip of a scanning tunneling microscope. While each triangulene unit has a total spin of 1, quantum correlations in the chain lead to spin fractionalization, such that the terminal triangulene units exhibit a spin of ½.

Quantum magic: sawing quantum magnets in half

All elementary particles have a ‘spin’, a fundamental property that governs their interaction with magnetic fields. Spins are quantized, which means they can only assume discrete values. Electrons have the smallest possible spin that can take two discrete values while the next simplest systems are those whose spin takes three discrete values – these are dubbed spin-½ and spin-1, respectively. In the 1980s, it was predicted that a one-dimensional chain of interacting spin-1 units should be ‘fractionalized’, such that the terminal units of the chain behave like spin-½ objects. Therefore, much like magicians who seem to saw a person in two halves and put them apart, quantum correlations in the chain divide a spin-1 in two spin-½ entities.

One dimensional magnetic chains assembled from molecules

Testing this prediction in a laboratory has been challenging for various reasons, chief among being that conventional materials are not one-dimensional. While indirect evidence of spin fractionalization has been seen in crystals of organometallic chains containing transition metal ions, a direct observation of the phenomenon has remained elusive.

Now, an international team of researchers has found a remarkable route to accomplish this feat. The team composed of organic chemists and local probe scientists fabricated chains of a [3]triangulene with spin 1. Using a scanning tunneling microscope (STM) the Empa-team then probed magnetic excitations of these chains on a gold surface. They found that beyond a certain length, the terminal triangulene units of the chains exhibited Kondo resonances – which are a characteristic spectroscopic fingerprint of spin-½ quantum objects in contact with a metal surface, as also evidenced by theoreticians.

Picture Left: Overview STM of a sample containing triangulene quantum spin chains, where chains containing between two to seven triangulene units are highlighted. Picture Right: High-resolution STM of a ten unit-long spin chain. The chemical structure of [3]triangulene is shown in the inset, where the blue arrows denote a spin-1 interaction between the unpaired electrons.

From chains to networks - and to quantum computers?

The researchers are convinced that such directly accessible molecular systems, which exhibit strongly correlated behavior of electrons, should become a fertile playground for testing new theoretical concepts. After exploring linear spin chains, the scientists will proceed to researching two-dimensional networks of quantum magnets. Such spin networks could possibly be used for quantum computing.

Reference: Shantanu Mishra, Gonçalo Catarina, Fupeng Wu, Ricardo Ortiz, David Jacob, Kristjan Eimre, Ji Ma, Carlo A. Pignedoli, Xinliang Feng^*, Pascal Ruffieux^*, Joaquín Fernández-Rossier^* and Roman Fasel “Observation of fractional edge excitations in nanographene spin chains” Nature, 2021, doi: 10.1038/s41586-021-03842-3

Acknowledgments: This work was supported by the Swiss National Science Foundation (grant numbers 200020-182015 and IZLCZ2-170184), the NCCR MARVEL funded by the Swiss National Science Foundation (grant number 51NF40-182892), the European Union’s Horizon 2020 research and innovation program (grant number 881603, Graphene Flagship Core 3), the Office of Naval Research (N00014-18-1-2708), ERC Consolidator grant (T2DCP, grant number 819698), the German Research Foundation within the Cluster of Excellence Center for Advancing Electronics Dresden (cfaed) and EnhanceNano (grant number 391979941), the Basque Government (Grant No. IT1249-19), the Generalitat Valenciana (Prometeo2017/139), the Spanish Government (Grant PID2019-109539GB-C41), and the Portuguese FCT (grant number SFRH/BD/138806/2018). Computational support from the Swiss Supercomputing Center (CSCS) under project ID s904 is gratefully acknowledged.

CSC-Award granted to Dr. Mingchao Wang and Dr. Shunqi Xu

October 7, 2021

Mingchao Wang and Shunqi Xu, postdoctoral researchers in the Chair of Molecular Functional Materials at TU Dresden, were selected to receive the "2020 Chinese Government Award for Outstanding Self-financed Students Abroad" by the China Scholarship Council. Congratulations!

Dr. Wang received his doctorate degree from Prof. Xinliang Feng’s group at TU Dresden in January 2021. His PhD study focused on the Phthalocyanine-Based Two-Dimensional Carbon-Rich Conjugated Frameworks.

Dr. Xu received his doctorate degree from Prof. Xinliang Feng’s group at TU Dresden in December 2020. His PhD study focused on the Cyano-substituted Two-dimensional Sp2-carbon-linked Conjugated Polymers.

This award recognizes their work for their PhD at Prof. Feng’s group.

The Chinese Government Award for Outstanding Self-financed Students Abroad was established by the China Scholarship Council in 2003 and aims at rewarding the academic excellence of self-financed Chinese students studying overseas. It is considered to be the highest award given by the Chinese government to graduate students studying aboard. Only those with outstanding performance in their PhD studies will be considered by the award panel and no more than 500 young talents will be granted the award each year all over the world.

Molecularly Engineered Black Phosphorus Heterostructures with Improved Ambient Stability and Enhanced Charge Carrier Mobility

September 24, 2021

Black phosphorus (BP) is an attractive layered semiconductor owing to a widely tunable bandgap (from 0.3 eV in bulk to 2 eV in the monolayer), inherent in-plane anisotropy, appealing charge-carrier mobility (1000 cm² V^-1 s^-1) as well as a broadband absorption from visible to mid-infrared range. All these features enable broad applications of BP in many fields, such as field-effect transistors (FETs), optoelectronic devices, energy conversion, energy devices. However, BP is highly vulnerable to oxygen and moisture due to abundant lone pair electrons at the BP surface. To address this problem, various chemical functionalization methods have been implemented to protect the BP sheets from oxidation. For example, covalent functionalization is an effective method to protect the topological structure of BP sheets. However, this strategy directly break P-P bonds thus largely compromise BP’ electronic properties. In contrast, non-covalent functionalization can preserve or modify the intrinsic properties of BP sheets to a large extent. However, it is generally less effective to regulate electronic properties of BP because of the weak interfacial coupling.

The researchers from the group of Prof. Xinliang Feng in collaboration with the group of Prof. Mischa Bonn (Max Planck Institute for Polymer Research) and Dr. Hai I. Wang (Max Planck Institute for Polymer Research) demonstrate an organic–inorganic hybrid heterostructure to enhance the stability of BP sheets and to tune simultaneously their electronic properties using hexaazatriphenylene derivatives (HATs). As electron acceptors, HATs can withdraw lone pair electrons from P atoms, resulting in a strong charge transfer from BP surface to HAT layer and leading to an improved ambient stability of BP/HATs sheets for up to 21 d. THz spectroscopic studies reveal that HATs substantially extend the scattering time of BP/HATs and yield a charge carrier mobility of 97 cm² V^-1 s^-1 for BP/HATs film, which is much higher than that of the pristine BP film (35 cm² V^-1 s^-1). The strategy opens up new avenues for versatile applications of BP sheets and provides an effective method for tuning the physicochemical properties of other air-sensitive 2D semiconductors.

Reference: Huanhuan Shi, Shuai Fu, Yannan Liu, Christof Neumann, Mingchao Wang, Haiyun Dong, Piotr Kot, Mischa Bonn, Hai I. Wang, Andrey Turchanin, Oliver G. Schmidt, Ali Shaygan Nia, Sheng Yang, Xinliang Feng. Molecularly Engineered Black Phosphorus Heterostructures with Improved Ambient Stability and Enhanced Charge Carrier Mobility, Adv. Mater. 2021, 2105694,

https://onlinelibrary.wiley.com/doi/10.1002/adma.202105694

Acknowledgments: This work was financially supported by Deutsche Forschungsgemeinschaft (MX-OSMOPED project), ERC Consolidator Grant on T2DCP, M-ERA-NET project HYSUCAP, SPES3 project funded by German Ministry for Education and Research (BMBF) under Forschung für neue Mikroelektronik (ForMikro) program and GrapheneCore3 881603. The authors thank Dr. Panpan Zhang, Dr. Zaichun Liu, Dr. Libo Ma, Dr. Kejun Liu, Dr. Haoyuan Qi, Dr. Zhen Zhang, and Dr. Markus Löffler for helpful discussions and characterization, and also acknowledge the Center for Advancing Electronics Dresden (cfaed), the Dresden Center for Nanoanalysis (DCN). Y.L. also acknowledges the Centre for Information Services and High Performance Computing (ZIH) in Dresden, Germany, for the provided computational resources. In addition, the authors acknowledge the support of computational calculations from Chenghao Liu in McGill University, Canada. H.S. and S.F. thank China Scholarship Council (CSC) for financial support. C.N. and A.T. acknowledge the financial support by FLAG-ERA “H2O” Project (DFG TU149/9-1) and SPP 2244 “2DMP” (DFG TU149/13-1).

NBN-Doped Bis-Tetracene and Peri-Tetracene: Synthesis and Characterization

September 14, 2021

The zigzag-edge rich polycyclic aromatic hydrocarbons (PAHs), such as bis-tetracene and peri-tetracene, have attracted increasing attention due to their unique electronic and magnetic properties. However, the instability of bis-tetracene and peri-tetracene caused by the open-shell character limits their further investigations. Thus far, two main strategies, sterically blocking the most reactive position (kinetic stabilization) and heteroatom doping (thermodynamic stabilization), have been established to synthesize stable zigzag-edged higher acenes. Specifically, the introduction of heteroatoms such as boron (B) or nitrogen (N) on the zigzag edges, not only provides access to stable heteroatom-doped acenes but also offers the possibility to tune their electronic structures.

The researchers from the group of Prof. Xinliang Feng in collaboration with the group of Prof. Hong-Jun Gao (Chinese Academy of Sciences) and Dr. Junzhi Liu (The University of Hong Kong) recently demonstrated the synthesis of NBN-doped bis-tetracene (NBN-BT) and peri-tetracene (NBN-PT) through combining solution-based and surface-assisted synthesis methods. Based on the high-resolution STM characterization, NBN-BT adopts a double-helical structure, while NBN-PT displays planar geometry, in which the atomically resolved structure of NBN-PT is further unveiled by nc-AFM characterization. Compared with their carbon-based analogs bis-tetracene (1.56 eV) and peri-tetracene (1.11 eV), the NBN-BT (2.48 eV) and NBN-PT (2.45 eV) exhibit excellent stability under ambient conditions, which is associated with their higher energy gap. Notably, through controlled continuous single-electron chemical or electrochemical oxidation, NBN-BT can be converted into its corresponding radical cation (0.88 eV) and further to dication (1.24 eV), which demonstrates a similar energy gap to its isoelectronic structure bis-tetracene (1.56 eV). This work opens up a new avenue for the synthesis of stable zigzag-edged nanographenes with multi-NBN units and paves the way for investigating the isoelectronic structures of pristine carbon-based zigzag-edged acenes.

Reference: Yubin Fu, Xiao Chang, Huan Yang, Evgenia Dmitrieva, Yixuan Gao, Ji Ma, Li Huang, Junzhi Liu, Hongliang Lu, Zhihai Cheng, Shixuan Du, Hong-Jun Gao, Xinliang Feng. NBN-Doped Bis-Tetracene and Peri-Tetracene: Synthesis and Characterization. Angew. Chem. Int. Ed. 2021, https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202109808

Acknowledgments: This work was supported by the European Union's Horizon 2020 (No 881603 Graphene Flagship Core3, No 813036 Marie Skłodowska-Curie), ERC Grant on T2DCP, German DFG (Cluster of Excellence “Center for Advancing Electronics Dresden (cfaed) and DFG-NSFC Joint Sino-German Research Project (EnhanceNano, No. 391979941), as well as the DFG-SNSF Joint Switzerland-German Research Project (EnhanTopo, No. 429265950). J. Liu is grateful for the funding support from the Hong Kong Research Grants Council (HKU 27301720) and ITC to the SKL. We thank the National Natural Science Foundation of China (Grant Nos. 61888102, and 61674045), the Ministry of Science and Technology (MOST) of China (No. 2019YFA0308500), as well as the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos. XDB30000000). We thank the Center for Information Services and High Performance Computing (ZIH) at TU Dresden for generous allocations of compute resources.

CRC 1415 Summer School  “Conductive Metal–Organic Frameworks - From Synthesis to Functions”

September 8, 2021

During the period from September 6 - 8 2021, the Priority Program (PP) 1928 "Coordination Networks: Building Blocks for Functional Systems - COORNETs", Technische Universität München, the Chair of Molecular Functional Materials and the Collaborative Research Centre (CRC) 1415 "Chemistry of Synthetic Two-Dimensional Materials" hosted the virtual Summer School "Conductive Metal-Organic Frameworks - From Synthesis to Functions". The in total 81 participants joined lectures by renowned scientists with focus on the synthesis, characterization and application of conductive metal-organic frameworks (MOFs). In addition, the poster presentations promoted the scientific exchange on further research topics and provided an ideal platform for networking for all participants.

We thank all Summer School participants for their contributions!

Interfacial Synthesis of Layer-Oriented 2D Conjugated Metal–Organic Framework Films toward Directional Charge Transport

August 26, 2021

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have emerged as a unique class of electronic materials, because they displayed the potential as active layers for electronic devices due to high conductivities (up to 2500 S cm^-1) and high carrier mobilities (up to 220 cm² V^-1 s^-1) with band-like transport property as well as tunable electronic structures. In the previous reports, a great effort was devoted to exploring electronic properties via the intralayer (basal plane) pathway because it was believed that the high conductivity of 2D c-MOFs depended critically on the full π-electron delocalization in the 2D conjugated plane. However, recent advances demonstrated that long-range charge transport in these layer-stacked framework materials could be primarily mediated via π–π stacking order. Therefore, controlled synthesis of layer-oriented 2D c-MOF films will be highly desirable to direct the charge transport along the interlayer or intralayer pathways and dial-in lateral/vertical electronic devices as well as further unveil the transport mechanism. Nevertheless, such investigations have never been addressed so far due to the challenge in controlling the stacking orientation of 2D c-MOFs in thin films.

The researchers from Prof. Xinliang Feng and Dr. Renhao Dong’s group recently presents the first demonstration of synthesizing unprecedented edge-on layer-orientated p-type semiconducting 2D c-MOF films (Cu₂[PcM-O₈], M=Cu, Fe) by combining supramolecular chemistry and interface-assisted polymerization. They figure out the crystal structure and orientations of the 2D c-MOFs films with molecular precision, and demonstrate that the edge-on structure formation is guided by the pre-organization of metal-phthalocyanine ligands, whose basal plane is perpendicular to the water surface due to their π-π interaction and hydrophobicity. The synthetic Cu₂[PcCu-O₈] film features with a thickness of ~20 nm and ~600 nm-sized crystal domains, and exhibits a room temperature conductivity of ~5.6×10^-4 S cm^-1 and a Hall mobility of ~4.4 cm² V^-1 s^-1 based on macroscopic van der Pauw pattern. Lateral and vertical measurements further reveal the directional charge transport feature in this edge-on 2D c-MOF film, i.e., the lateral conductivity is 2~3 orders of magnitude higher than the vertical one. The directional conductivity studies combined with theoretical calculation identify that the intrinsic conductivity of Cu₂[PcCu-O₈] is dominated by charge transfer along the interlayer pathway.

Reference: Z. Wang, L. S. Walter, M. Wang, P. S. Petkov, B. Liang, H. Qi, N. N. Nguyen, M. Hambsch, H. Zhong, M. Wang, S. Park, L. Renn, K. Watanabe, T. Taniguchi, S. C. B. Mannsfeld, T. Heine, U. Kaiser, S. Zhou, R. T. Weitz, X. Feng, R. Dong, Interfacial Synthesis of Layer-Oriented 2D Conjugated Metal–Organic Framework Films toward Directional Charge Transport, J. Am. Chem. Soc. 2021, https://pubs.acs.org/doi/10.1021/jacs.1c05051

Acknowledgments: This work is financially supported by EU Graphene Flagship (Core3, No. 881603), ERC starting grant (FC2DMOF, No. 852909), ERC Consolidator Grant (T2DCP), DFG projects (SFB-1415, No. 417590517, SPP 1928, WE 4893/6-1, COORNET), H2020-MSCA-ITN (ULTIMATE, No. 813036), as well as the German Science Council and Center of Advancing Electronics Dresden (cfaed). Z.W. gratefully acknowledges funding from the China Scholarship Council. R.T.W. acknowledges funding from the Center for Nanoscience (CeNS) and the Solar Technologies go Hybrid (SolTech) initiative as well as funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy-EXC-2111-390814868 (MCQST) and EXC 2089/1-390776260 (e-conversion). K.W. and T.T. acknowledge support from the Elemental Strategy Initiative conducted by the MEXT, Japan, A3 Foresight by JSPS, and the CREST (JPMJCR15F3), JST. K.W. and T.T. acknowledge support from the EMEXT Element Strategy Initiative to Form Core Research Center, Grant Number JPMXP0112101001 and the CREST (JPMJCR15F3), JST. P.S.P. and T.H. thank ZIH Dresden for providing high-performance computing facilities. We acknowledge Elettra Sincrotrone Trieste for providing access to its synchrotron radiation facilities and we thank Luisa Barba for assistance in using beamline XRD1. The research leading to this result has been supported by the project CALIPSOplus under Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020.

Guest Visit Prof. Dr. Klaus Müllen

COORNET Summer School

Online Guest lecture - Dr. Holger Meyerheim, Max Planck Institute of Microstructure Physics, Halle

Online Guest lecture - Prof. Chunyi Zhi, Department of Materials Science & Engineering, City University of Hong Kong, China

Dual Active Sites Conjugated Acetylenic Polymers for Photoelectrochemical Water Reduction in Alkaline Medium

July 15, 2021

Photoelectrochemical (PEC) water splitting is a promising technology for hydrogen production combining the inexhaustible solar energy and the electrolysis of water. A variety of inorganic materials including inorganic metal oxides, transition-metal dichalcogenides and metal sulphides have been reported as photocathodes materials; however, their need of co-catalysts, the high costs and the photocorrosion have been hindered their practical application.
Synthetic organic materials are emerging as an interesting class of photocathodes due to their intrinsic advantages over the inorganic counterparts. These include the broader absorption of the solar spectrum, the molecular tunability of band gaps and energy levels positions and the facile synthesis. So far, they have only been reported under acidic or neutral conditions, facilitated by the high concentration of protons; in alkaline medium, on the other hand, they still show poor performance due to the lack of water dissociation sites, which are needed to produce the required protons.
The researchers from the group of Prof. Xinliang Feng in collaboration with the group of prof. Inez Weidinger (TU Dresden) overcame this issue in the work Thiophene-based Conjugated Acetylenic Polymers with Dual Active Sites for Efficient Co-Catalyst-free Photoelectrochemical Water Reduction in Alkaline Medium, recently published in Angewandte Chemie.
Using a molecular engineering strategy, highly efficient active sites for water dissociation were incorporated in conjugated acetylenic polymers (CAPs) by modifying the polymer skeleton from poly(diethynylthieno[3,2-b]thiophene) (pDET) to poly(2,6-diethynylbenzo[1,2-b:4,5-b’]dithiophene (pBDT) and poly(diethynyldithieno[3,2-b:2’,3’-d]thiophene) (pDTT).
The as-synthesized pDTT and pBDT grown on Cu substrate demonstrated benchmark photocurrent densities of 170 mAcm^-2 and 120 mAcm^-2 (at 0.3 V vs. RHE; pH 13), which are 4.2 and 3 times higher than that of pDET.
Density Functional Theory (DFT) and electrochemical-operando resonance Raman spectroscopy reported that the C_β of the outer thiophene rings are the water dissociation active sites, while the diacetylenic linkages function as electrocatalytic active sites. These findings will pave the way to design new and more efficient photocathodes.

Reference: Borrelli, C. J. Querebillo, D. L. Pastoetter, T. Wang, A. Milani, C. Casari, H. K. Ly, F. He, Y. Hou, C. Neumann, A. Turchanin, H. Sun, I. M. Weidinger, X. Feng, Thiophene-based Conjugated Acetylenic Polymers with Dual Active Sites for Efficient Co-Catalyst-free Photoelectrochemical Water Reduction in Alkaline Medium, Angew. Chem. Int. Ed. 2021, 60, 2–8, …/doi/10.1002/anie.202104469

Acknowledgments: This work was financially supported by the Graphene Flagship (GrapheneCore3, No. 881603) and ERC Grant (T2DCP, No. 819698). We acknowledge the cfaed (Center for Advancing Electronics Dresden) and the Dresden Center for Nanoanalysis (DCN) at TU Dresden. I.W. acknowledges the cluster of excellence UniSysCat (EXC 2008/1 -390540038). C.S. and A.M. acknowledge ERC Grant (CoG 2016 EspLORE, No. 724610). A.T. and C.N. acknowledge DFG TRR 234 “CataLight” (B7 and Z2) and research infrastructure grant INST 275/257‐1. M.B. thanks Dr. Tao Zhang, Huanhuan Shi, Dr. Markus Löffler (DCN), and Dr. Zhongquan Liao for preliminary characterization, Dr. Moritz Kuehnel and Dr. Uttam Gupta for preliminary measurements, Dr. Jian Zhang and Dr. Ahiud Morag for fruitful discussions and prof. Fabrizia Negri for preliminary calculations. C.J.Q. acknowledges Markus Göbel for his helpful suggestions.

Synthetic tuning of the quantum properties of open-shell radicaloids

July 13, 2021

Molecular compounds are emerging as appealing units for quantum computation and quantum technologies. For these purposes open-shell molecular radicaloids hold exceptional interest: they offer π-conjugated units with an unpaired electron ground state and they can be considered as atomically-precise pieces of graphene. The next frontier to improve the quantum performance is to determine structure-quantum properties relations, such as how the size of the extended π-systems affects the coherence properties, or how the molecular geometry and electron-nuclear interactions determine the coherence time, so as to channel the synthetic efforts towards blocking decoherence pathways.

The scientists from TU Dresden/Oxford university have established the links between morphology and quantum properties, using three related radicaloids (1, 2 and 3) based on meta-quinodimethane. The roles of the π-conjugated backbone and of the side groups on the spin-flip and quantum coherence times are unraveled. The temperature regions are identified, where different structural parts of the molecule or solvent become the dominant decoherence channel. The record quantum coherence values obtained at room temperature are still well below the intrinsic limits of radicaloids, and the researchers further discuss the directions to optimize the quantum performance. This fruitful work of the joint research has been now published in the renowned journal “Chem” as an article.

Acknowledgments: The authors gratefully acknowledge financial support by the EU Horizon 2020 (ERC-CoG-MMGNRs-773048 and ERC-CoGT2DCP-881603, Graphene Flagship Core3 813036, Marie-Curie program), Royal Society (RS grant and URF), EPSRC (grant no. EP/N509711/1, EP/R042594/1, and EP/L011972/1), German DFG (Cluster of Excellence ‘‘Center for Advancing Electronics Dresden (cfaed)’’) and EnhanceNano-391979941, the European Social Fund and the Federal State of Saxony (ESFProject ‘‘GRAPHD,’’ TU Dresden).

Reference: Fedrico Lombardi, Ji Ma, Hartmut Komber, Dimitris I. Alexandropoulos, Junzhi Liu, William K. Myers, Xinliang Feng, Lapo Bogani, Synthetic Tuning the Quantum Properties of Open-shell Radicaloids, 2021, 7(5), 1363-1378.

Dual-Redox-Sites Enable Two-Dimensional Conjugated Metal–Organic Frameworks with Large Pseudocapacitance and Wide Potential Window

July 13, 2021

Advanced supercapacitor electrodes require the development of materials with dense redox-sites embedded into conductive and porous skeletons. Two-dimensional (2D) conjugated metal-organic frameworks (c-MOFs) are attractive supercapacitor electrode materials due to their high intrinsic electrical conductivities, large specific surface areas, and quasi-one-dimensional aligned pore arrays. However, the reported 2D c-MOFs still suffer from unsatisfying specific capacitances and narrow potential windows because large and redox-inactive building blocks lead to low redox-site densities of 2D c-MOFs.

The researchers from Prof. Xinliang Feng’s group recently demonstrated the dual-redox-site 2D c-MOFs with copper phthalocyanine building blocks linked by metal-bis(iminobenzosemiquinoid) (M₂[CuPc(NH)₈], M = Ni or Cu), which depict both large specific capacitances and wide potential windows. Experimental results accompanied by theoretical calculations verify that phthalocyanine monomers and metal-bis(iminobenzosemiquinoid) linkages serve as respective redox sites for pseudocapacitive cation (Na⁺) and anion (SO₄^2-) storage, enabling the continuous Faradaic reactions of M₂[CuPc(NH)₈] occurring in a large potential window of −0.8 ~ 0.8 V vs. Ag/AgCl (3 M KCl). The decent conductivity (0.8 S m⁻¹) and high active-site density further endow the Ni₂[CuPc(NH)₈] with a remarkable specific capacitance (400 F g⁻¹ at 0.5 A g⁻¹) and excellent rate capability (183 F g⁻¹ at 20 A g⁻¹). Quasi-solid-state symmetric supercapacitors are further assembled to demonstrate the practical application of Ni₂[CuPc(NH)₈] electrode, which deliver a state-of-the-art energy density of 51.6 Wh kg⁻¹ and a peak power density of 32.1 kW kg⁻¹. This work provides insightful guidelines for exploring the multielectron Faradaic reactions in new porous framework materials, which will benefit the development of next-generation energy storage technologies.

Reference: Panpan Zhang, Mingchao Wang, Yannan Liu, Sheng Yang, Faxing Wang, Yang Li, Guangbo Chen, Zichao Li, Gang Wang, Minshen Zhu, Renhao Dong, Minghao Yu, Oliver G Schmidt, Xinliang Feng. Dual-Redox-Sites Enable Two-Dimensional Conjugated Metal–Organic Frameworks with Large Pseudocapacitance and Wide Potential Window. J. Am. Chem. Soc. 2021, https://pubs.acs.org/doi/abs/10.1021/jacs.1c03039

Acknowledgments: This work was financially supported by European Union’s Horizon 2020 research and innovation programme (GrapheneCore3 881603), ERC Consolidator grant (T2DCP 819698), ERC Starting grant (FC2DMOF, No. 852909), Deutsche Forschungsgemeinschaft (MX‐OSMOPED), M-ERA.NET and Sächsisches Staatsministerium für Wissenschaft und Kunst (HYSUCAP 100478697), German Research Foundation (DFG) within the Cluster of Excellence, CRC 1415 (grant no. 417590517), Polymer-based Batteries (SPP 2248, RACOF-MMIS), and Coordination Networks: Building Blocks for Functional Systems (SPP1928, COORNETs). We appreciate Dr. Mao Wang for the conductivity measurements and thank Dr. Yulia Krupskaya (IFW Dresden) for EPR measurement. We acknowledge the use of the facilities in Dresden Center for Nanoanalysis at Technische Universität Dresden. The authors thank the Center for Information Services and High Performance Computing (ZIH) at TU Dresden for generous allocations of computer time.

Press Trip Greentech City Dresden

July 8, 2021

The Chair of Molecular Functional Materials, Sixonia Tech GmbH and the Collaborative Research Centre 1415 were pleased to welcome Greentech City Dresden for a short visit on July 8, 2021. The visit of a total of 3 journalists (Sächsische Zeitung, Oiger, IntoVR/Welt) and representatives of the city of Dresden included scientific presentations, demonstrations and interviews.

We thank all participants for their contribution to an exciting press visit!

https://oiger.de/2021/07/12/biegsame-stromspeicher-fuer-feuerwehr-kuehljacken/179856

https://www.dresden.de/de/wirtschaft/tomorrow-s-home/greentech/cfaed-dt.php

Online Guest lecture - Kai-Qiang Lin, Department of Physics, University of Regensburg, Germany

CRC 1415 - Virtual Retreat 2021

May 31, 2021

The consortium of the CRC 1415 organized its first online-based retreat from May 27-28, 2021 with the aim of promoting interaction, communication and teamwork between the members of the CRC 1415.

During two eventful days, the scientific advances in the research areas A (material synthesis), B (characterization) and C (theory) were presented and discussed, taking into account all 22 sub-projects. Furthermore, the retreat participants came together in two virtual poster exhibitions, organized by the doctoral students: inside the Integrated Graduate School 2D Materials (MGK-2DMs). As part of the poster exhibitions, the MGK-2DMs awarded three poster prizes to doctoral students for outstanding performance and presentation inside the CRC 1415. The winners of this years’s MGK-2DMs poster exhibition chosen by the CRC members are: Paula Kalenczuk (1^st place), Ankita De (2^nd place) and Friedrich Schwotzer (3^rd place).

MGK Poster Award Winner

Another highlight of the retreat was the guest lecture by Prof. Cinzia Casiraghi, University of Manchester, Great Britain. Her lecture “Water-based, error-free and biocompatible 2D material inks: From printed devices to biomedical applications” was met with great interest from all participants and we thank Prof. Casiraghi very much for her contribution to the CRC 1415 Retreat 2021!

Guest Lecture Prof. Cinzia Casiraghi

In addition to the scientific exchange, team development and the promotion within the CRC 1415 was not neglected either. An exciting online escape room team event rounded off the evening on the first day of the event. In the Escape Room team event, the CRC members went on a mission together to track down the jewel thief using logical thinking, creativity and communication.

Diamond Fever ©Eplayces

The 2021 retreat concluded with the 3rd General Assembly on the afternoon of May 28th.

Persistent peri-Heptacene: Synthesis and In-Situ Characterization

April 19, 2021

The synthesis of the longest peri-acene, i.e., peri-Heptacene (7-PA) is accomplished by the researchers from the group of Prof. Xinliang Feng in collaboration with Politecnico di Milano, Leibniz Institute for Solid State and Materials Research, and Leibniz-Institut for Polymerforschung Dresden e. V. The work has recently reported as a communication “Persistent peri-Heptacene: Synthesis and In-Situ Characterization” in Angewandte Chemie International Edition. n-peri-Acenes (n-PAs) have gained enormous interest as fundamental model systems of zigzag-edged graphene nanoribbons for the potential applications in synthetic carbon nanoelectronics and spintronics. However, the synthesis of n-PAs larger than peri-tetracene (4-PA) remains challenging because of their intrinsic open-shell character and high reactivity. In this communication, the authors reported the synthesis of the hitherto unknown 7-PA, by a rational molecular design strategy, in which the reactive zigzag edges are kinetically protected with eight 4-tert-butylphenyl groups. The successful formation of 7-PA from its tetrahydro-precursor 3 was clearly validated by high-resolution mass spectrometry and in-situ FT-Raman spectroscopy. The resultant 7-PA displays a narrow optical energy gap of 1.01 eV and exhibits a persistent stability (half-life, t_1/2 ~ 25 min) under inert conditions. Moreover, electron spin resonance (ESR) measurements and theoretical studies reveal that 7-PA exhibits an open-shell feature and a significant tetraradical character (y₀ = 1.0 and y₁ = 0.2). This synthetic strategy could be considered as a modular approach for the construction of next generation (3N+1)-PAs (where N = 3, 4, etc.).

 

 

Reference: M. R. Ajayakumar, J. Ma, A. Lucotti, K. S. Schellhammer, G. Serra, E. Dmitrieva, M. Rosenkranz, H. Komber, J. Liu, F. Ortmann, M. Tommasini, and Xinliang Feng, Angew. Chem. Int. Ed. 2021, https://doi.org/10.1002/anie.202102757

Acknowledgments:  This research was financially supported by the EU Graphene Flagship (Graphene Core 3, 881603), ERC Consolidator Grant (T2DCP, 819698), the Center for Advancing Electronics Dresden (cfaed) and DFG-NSFC Joint Sino-German Research Project (EnhanceNano, No. 391979941), as well as the DFG-SNSF Joint Switzerland-German Research Project (EnhanTopo, No. 429265950). We thank Mr. Federico Lombardi and Prof. Dr. Lapo Bogani for helpful discussions. The authors acknowledge the use of computational facilities at the Center for information services and high performance computing (ZIH) at TU Dresden. J. Liu is grateful for the startup funding from The University of Hong Kong. G.S. and M.T acknowledge funding by the Italian Ministry of Education, Universities and Research (MIUR) through the PRIN 2017 program (Project No. 2017PJ5XXX “MAGIC DUST”).

 

A Two-Dimensional Polyimide-Graphene Heterostructure with Ultra-fast Interlayer Charge Transfer

April 15, 2021

The researchers from the group of Prof. Xinliang Feng and Dr. Renhao Dong recently reported the paper “A Two-Dimensional Polyimide-Graphene Heterostructure with Ultra-fast Interlayer Charge Transfer” in Angewandte Chemie International Edition. This is a joint work of TU Dresden, Leibniz-Institut für Polymerforschung Dresden, , Helmholtz-Zentrum Dresden-Rossendorf, and Universität Ulm.
A two-dimensional polymer (2DP) is a sheet-like monomolecular macromolecule consisting of laterally connected repeat units with end groups along all edges. Given the single-atom or -molecule thickness, enormous chemical and structural diversity, 2DPs hold great promise as ideals candidates for van der Waals heterostructures (vdWHs) by stacking different 2D crystals on top of each other. However, the synthesis of 2DP-based vdWHs is still problematic. Firstly, there are tremendous challenges for precisely synthesizing well-defined crystalline monolayer 2DP at molecule level. Secondly, how to realize the transfer and stacking of 2DPs is still unexplored. Thirdly, there should be strong interlayer interaction in vdWH to show new physical properties, which is hard to realize due to the poor long-range ordering of 2DPs.
In recent years, air-water interfacial synthesis is rapidly developing to prepare large-area, free-standing, mono- or few-layer 2DPs, paving the way to synthesize 2DP-based vdWHs. Based on previous work, the research group led by Prof. Feng and Dr Dong used Langmuir–Blodgett technique to synthesize monolayer 2D polyimide (2DPI). Furthermore, the 2DPI film was fabricated with graphene via van der Waals force to prepare a 2DPI-Graphene hybrid material.
Transient absorption (TA) spectroscopy proved that there was ultra-fast (~60 fs) charge transfer from protonated 2DPI to graphene under UV radiation, which can compare with the best records of inorganic vdWH materials. The charge transfer was attributed to the strong cation-π interaction between graphene and protonated 2DP. This work offers an effective strategy for preparing 2DP-based vdWH and discovers a unique charge transfer property due to interfacial electron coupling.

Figure 1. Bottom: A general but reliable on-water synthesis and assembly strategy toward the preparation of 2D polyimide (2DPI)-graphene (G) van der Waals heterostructures (vdWHs) on the water surface is demonstrated. Top: femtosecond transient absorption spectroscopy reveals an ultra-fast interlayer charge transfer (~60 fs) after protonation in the heterostructure, which is among the fastest reports of vdWHs.

Reference: Liu, K., Li, J., Qi, H., Hambsch, M., Rawle, J., Vázquez, A.R., Nia, A.S., Pashkin, A., Schneider, H., Polozij, M., Heine, T., Helm, M., Mannsfeld, S.C.B., Kaiser, U., Dong, R., Feng, X., 2021. A Two‐Dimensional Polyimide‐Graphene Heterostructure with Ultra‐fast Interlayer Charge Transfer. Angewandte Chemie.. doi:10.1002/ange.202102984

Acknowledgments: We acknowledge financial support from EU Graphene Flagship (Core3, No. 881603), ERC Grants on T2DCP and FC2DMOF (No. 852909) and DFG projects (SFB-1415, No. 417590517; SPP 2244, 2DMP) as well as the German Science Council, Centre of Advancing Electronics Dresden, EXC1056 (Center for Advancing Electronics Dresden) and OR 349/1. We thank Prof. Xiaodong Zhuang (Shanghai Jiao Tong University) and Prof. Zhikun Zheng (Sun Yat-sen University) for fruitful discussions. We acknowledge Dresden Center for Nanoanalysis (DCN) for scanning electron microscopy and Dr. Petr Formanek (Leibniz Institute for Polymer Research, IPF, Dresden) for the use of facilities.. We acknowledge Diamond Light Source for time on Beamline I07 under Proposal SI25070.

 

Vinylene-Linked Two-Dimensional Covalent Organic Frameworks: Synthesis and Functions

March 31, 2021

Two-dimensional conjugated covalent organic frameworks (2D-c-COFs) with covalently bonded repeat units, crystalline and porous frameworks, and in-plane π-conjugations have attracted immense attention. The precise structure and predictable properties of 2D-c-COFs can be applied to specific applications, such as energy storage/conversion, and optoelectronics. In particular, over the last five years, vinylene-linked 2D covalent organic frameworks (V-2D-COFs) have been extensively explored due to their high in-plane π-conjugation and robust nature.
In this Account, we summarized the important developments of V-2D-COFs, from synthetic methods to unique physical properties and functions. For the synthetic methodologies, three reaction methodologies are introduced, including the Knoevenagel-, other aldol-type-, and Horner-Wadsworth-Emmons polycondensations. Afterward, the optoelectronic and magnetic properties of V-2D-COFs are presented. Finally, the promising applications of V-2D-COF, including sensing, photocatalysis, energy storage and conversion are further demonstrated, which demonstrate the merits resulting from the robust vinylene-linked skeleton, full in-plane π-conjugation, and tunable structures.

 

 

Reference: Shunqi Xu, Marcus Richter, and Xinliang Feng*. Vinylene-Linked Two-Dimensional Covalent Organic Frameworks: Synthesis and Functions. Acc. Mater. Res. 2021. doi.org/10.1021/accountsmr.1c00017.

Acknowledgments: This work was supported financially by the EU Graphene Flagship (Graphene Core, No. 881603), the Collaborative Research Center (CRC) 1415 “Chemistry of Synthetic Two-Dimensional Materials” (No. 417590517), H2020-MSCA-ITN (ULTIMATE, No. 813036), the Center for Advancing Electronics Dresden (cfaed), and the ERC Consolidator Grant (T2DCP, No. 819698). We thank Dr. Naisa Chandrasekhar, Prof. Bishnu P. Biswal, M. Sc. Dominik Pasoetter and M. Sc. Albrecht Waentig for the helpful discussion.

 

Prof. Xinliang Feng joins the Max Planck Institute of Microstructure Physics as new Director

March 15, 2021

Prof. Dr. Xinliang Feng will join the Max Planck Institute of Microstructure Physics as a new Director on Monday, March 15, 2021. He will lead the Department of Synthetic Materials and Functional Devices at the Institute.

Link to website of MPI Halle

Prof. Dr. Xinliang Feng will also continue to run the chair for Molecular Functional Materials at TU Dresden.

Prof. Xinliang Feng acted as Guest Editor for the Royal Society of Chemistry's online collection in Nanoscale and Nanoscale Advances

March 15, 2021

Prof. Dr. Xinliang Feng has acted as Guest Editor for the Royal Society of Chemistry's online themed collection in Nanoscale and Nanoscale Advances and contributed articles on the Chemistry of 2D Materials: graphene and beyond.

Link to the collection

Dr. Shaygan Nia recently interviewed by EU Graphene Flagship

February 26, 2021

Dr. Shaygan Nia, the Innovation group leader of the chair, was recently interviewed by EU Graphene Flagship and gave his thoughts on the current and potential application of Graphene and 2D materials Foams and Coatings.

EU Graphene Flagship Innovation Newsletter Issue 1,2021

Congratulations to Guangbo Chen for successfully defending his PhD

February 17, 2021

Guangbo Chen successfully defended his PhD on “Carbon-rich Nanomaterials for Electrocatalytic Oxygen Reduction Reactions” on February 16, 2021. Congratulations Dr. Chen!

Congratulations to Mingchao Wang for successfully defending his PhD

January 25, 2021

Mingchao Wang successfully defended his PhD on “Phthalocyanine-Based Two-Dimensional Carbon-Rich Conjugated Frameworks” on January 25, 2021. Congratulations Dr. Wang!

Designer Spin Order in Diradical Nanographenes

January 18, 2021

Researchers from the Chair of Molecular Functional Materials of Prof. Xinliang Feng, Technische Universität Dresden, and the research group of Jinfeng Jia, Condensed Matter Physcics, School of Physics and Astronomy Shanghai Jiao Tong University, recently reported the joint paper “Designer Spin Order in Diradical Nanographenes”. The magnetic properties of carbon materials are at the focus of research effort in physics, chemistry and materials science due to their potential applications in spintronics and quantum computing. Although the presence of spins in open-shell nanographenes has recently been confirmed, the ability to control magnetic coupling sign has remained elusive. Here, the researchers demonstrate an effective approach of engineering magnetic ground states in atomically precise open-shell bipartite/nonbipartite nanographenes using combined scanning probe techniques and mean-field Hubbard model calculations. The method provides opportunities for designer above-room-temperature magnetic phases and functionalities in graphene nanomaterials.

 

 

Reference:

Designer Spin Order in Diradical Nanographenes

Yuqiang Zheng, Can Li, Chengyang Xu, Doreen Beyer, Xinlei Yue, Yan Zhao, Guanyong Wang, Dandan Guan, Yaoyi Li, Hao Zheng, Canhua Liu, Junzhi Liu, Xiaoqun Wang, Weidong Luo, Xinliang Feng, Shiyong Wang Jinfeng Jia.

Nature Communications 11, Article number: 6076 (2020).

This work was financially supported by the National Natural Science Foundation of China (No. 11874258, 12074247) and Fok Yin Tung foundation. J.L. is grateful for the startup funding from the University of Hong Kong and the funding support from ITC to the SKL. This work is also supported by the Ministry of Science and Technology of China (Grants No. 2016YFA0301003, No. 2016YFA0300403), the National Natural Science Foundation of China (Grants No. 11521404, No. 11634009, No. 11574202, No. 11874256, No. 11790313, No. 11674226, No. U1632102, No. 11674222, No. U1632272 and No. 11861161003), and the Strategic Priority Research Program of Chinese Academy of Sciences (Grant No. XDB28000000). We acknowledge SJTU HPC center for providing computational resources.

 

High-Mobility Semiconducting Two-Dimensional Conjugated Covalent Organic Frameworks with p-Type Doping

January 18, 2021

Two-dimensional conjugated covalent organic frameworks (2D c-COFs) have recently emerged as a unique class of 2D conjugated polymers that display high in-plane π-conjugation and weak out-of-plane interactions. Because of their tailorable architectures, abundant active sites, well-defined structures, inherent porosity, chemical stability, and (opto)-electronic properties, these materials are promising for chemiresistors, logic and memory devices, and energy storage. For many of these applications, long-range charge transport is required. Therefore, much effort has been devoted over the last years to interrogate the nature of the conductivity in 2D c-COFs. Recent studies have demonstrated charge carrier mobilities ranging from 5 to 8 cm²/(Vs). Although these mobilities are encouraging, their conductivities have remained rather low (typically <10^-6 S/cm). To further improve the conductivity, doping strategies have been employed by incorporating guest molecules that act as dopants, e.g., linear conducting polymers, C₆₀, iodine (I₂), etc. For instance, I₂-doping has demonstrated improvement of up to 3 orders of magnitude in the conductivities, but this approach was often associated with amorphization/irreversible structural changes of 2D c-COFs. A fundamental understanding of the doping interactions within the lattice in COFs remains largely unexplored.

 

 

In order to investigate the role of dopant for 2D c-COFs, researchers from Technical University of Dresden (Chair for Molecular Functional Materials) and collaborators have demonstrated a doping-defined polycrystalline 2D c-COF (ZnPc-pz-I₂) through molecular I₂-doping of metal-phthalocyanine-based pyrazine-linked 2D c-COF ZnPc-pz. I₂-molecules sit preferentially in the COF pores and near the skeleton. Hall effect measurements reveal that doping improves the conductivity and carrier density by approximately 3 and 2 orders of magnitude respectively in ZnPc-pz-I₂. Notably, doping also leads to an unprecedented improvement in the Hall charge mobility from ~5 to ~22 cm²/(Vs). Density functional theory (DFT) and time-resolved terahertz spectroscopy (TRTS) show that this record mobility is related to an increase in the scattering time after doping, likely related to the formation of ordered pathways for charge carrier migration between the electron donor (ZnPc-pz) and acceptor (I₂) within the framework. Such unique phenomena have never been reported among doped COF materials. This work highlights the potential of developing structurally-defined, doped 2D c-COFs with high conductivity and high mobility, which provides insight on a fundamental understanding of the role of the dopant and the host-dopant interplay necessary to elucidate structure-electronic property relationships.

This work is financially supported from EU Graphene Flagship (GrapheneCore3, No. 881603), ERC Grants (T2DCP and FC2DMOF (No. 852909)), H2020-MSCA-ITN (ULTIMATE, No. 813036), DFG projects (COORNETs, SPP 1928 and CRC 1415, No. 417590517), the German Science Council, Center for Advancing Electronics Dresden (EXC1056), the regional government of Comunidad de Madrid under projects 2017-T1/AMB-5207 & P2018/NMT-4511, as well as the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grant No. SEV-2016-0686).

 

Reference:

Mingchao Wang, Mao Wang, Hung-Hsuan Lin, Marco Ballabio, Haixia Zhong, Mischa Bonn, Shengqiang Zhou, Thomas Heine, Enrique Cánovas*, Renhao Dong*, Xinliang Feng*. High-Mobility Semiconducting Two-Dimensional Conjugated Covalent Organic Frameworks with p-Type Doping. J. Am. Chem. Soc. 2020, 142, 52, 21622–21627.

https://pubs.acs.org/doi/abs/10.1021/jacs.0c10482

 

Congratulations to SangWook Park for successfully defending his PhD

December 22, 2020

SangWook Park successfully defended his PhD on “Two-Dimensional Organic Framework Films by Amphiphilic Compound Assisted Interfacial Synthesis” on December 16, 2020. Congratulations Dr. Park!

Congratulations to Shunqi Xu for successfully defending his PhD

December 22, 2020

Shunqi Xu successfully defended his PhD on “Cyano-substituted Two-dimensional Sp2-carbon-linked Conjugated Polymers” on December 11, 2020. Congratulations Dr. Xu!

Dr. Chuanhui Huang received the prestigious Humboldt Research Fellowship for Postdoctoral Researchers

December 22, 2020

The Humboldt Research Fellowship is awarded to researchers from abroad with above average qualifications and who are at the beginning of their career. By being granted this fellowship, Dr. Chuanhui Huang, will receive financial support for two years to carry out his research in the research group of Prof. Xinliang Feng and Dr. Renhao Dong at Technische Universität Dresden.

Highly Cited Researcher 2020

December 9, 2020

Prof. Dr. Xinliang Feng has been listed as highly cited researcher in 2020 - in the categories Chemistry and Materials Science - for his research performance demonstrated by the production of multiple highly cited papers that rank in the top 1% by citations for field and year in Web of Science.

Dr. Minghao Yu, research group leader in Prof. Feng's group, has been listed as well as highly cited researcher in 2020 in the category Materials Science.

Former colleagues in the group of Prof. Feng, Dr. Yang Hou and Dr. Xiaodong Zhuang, are also among the highly cited researchers in 2020 in the Cross-Field category.

https://recognition.webofscience.com/awards/highly-cited/2020/

Ground-breaking Ceremony for New Office and Laboratory Building at TU Dresden

November 25, 2020