Development of Functional Conjugated Two-Dimensional Metal-Organic Frameworks

Project Information

FC2DMOF

Grant agreement ID: 852909

DOI

10.3030/852909

Project closed

EC signature date 7 October 2019

Start date 1 February 2020

End date 31 January 2025

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 500 000,00

EU contribution

€ 1 500 000,00

Coordinated by

TECHNISCHE UNIVERSITAET DRESDEN
Germany

Periodic Reporting for period 4 - FC2DMOF (Development of Functional Conjugated Two-Dimensional Metal-Organic Frameworks)

Reporting period: 2024-08-01 to 2025-01-31

Summary of the context and overall objectives of the project

The rapid development of modern technologies, from smartphones to solar panels, relies heavily on new materials that can conduct electricity, store energy, and respond to external stimuli. However, most of the materials used today are either expensive, difficult to recycle, or lack the flexibility needed for next-generation applications like wearable electronics or smart windows. FC2DMOF tackled this challenge by developing a new class of materials called two-dimensional conjugated metal–organic frameworks (2D c-MOFs).
The recent researches have demonstrated that 2D c-MOFs, as another unique class of electronic materials, are emerging to provide additional possibility for multifunctional electronic devices that brings us “MOFtronics”. 2D c-MOFs have similar structural features to graphite and other van der Waals layer-stacked materials, and in recent years have displayed much higher conductivities (up to 2,500 S cm-1) than conventional 3D MOFs (<10-8 S cm-1) or demonstrated charge mobility of 220 cm2 V s-1 with band-like transport (Nat. Mater. 2018,17,1027). So far, around 30 2D c-MOFs have been reported based on planar polycyclic aromatic ligands with symmetrical functional groups (Nat. Mater. 2021, 20, 122; Chem. Soc. Rev. 2021, 50, 2764). However, chemical knowledge of how to construct single-crystalline 2D c-MOF bulk and film samples by molecular and synthetic design has remained a mystery. The development on reliable electronic and spintronic devices with superior performances has been rather limited.
Our overall objectives are listed below:
1. Develop novel synthetic strategies for producing high quality 2D conjugated metal organic framework (2D c-MOF) thin films with controlled thickness, crystallinity, and orientation especially through interfacial synthesis methods.
2. Investigate and optimize charge transport in 2D c-MOFs by correlating their molecular design, crystallographic structure, and electronic properties, aiming to achieve high intrinsic charge mobility and high conductivity materials.
3. Explore functional applications of 2D c-MOFs as “MOFtronics”. Including electronics and optoelectronics devices, electrocatalysis and energy storage materials, sensors and smart functional materials, Spin devices and magnetic devices.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

FC2DMOF generated exciting achievements, which have been globally leading the development of “MOFtronics”.
1) Design and synthesis of novel conjugated ligands for the fine engineering of lattice structures and the tailoring of the electronic and magnetic structures. We designed and synthesised more than 8 series of 25 kind of ligands, and successfully prepared more than 40 kind of brand new 2D-cMOF structures, which largely broaden the diversity of 2D-cMOF structures. According to the characteristics of each structures, we developed specific applications of each and achieved our conception of “MOFtronics”.
2) Development of highly efficient synthetic methodologies toward bulk single crystals and thin-film samples, such as solution synthesis, delamination strategies, liquid-interface-assisted synthesis and chemical vapour deposition (CVD) synthesis. A major achievement was the fabrication of large-area, oriented, crystalline thin films of 2D c-MOFs with controllable morphology and thickness, as well as the ultrasmooth MOF films fabricated by CVD method. These materials served as a platform for investigating charge transport properties, and we demonstrated band-like transport behavior with high charge carrier mobility—an unprecedented finding in the field. Representing a critical advance for incorporating MOFs into electronic and optoelectronic devices.
3) Construction of unprecedented van der Waals heterostructures and broaden their applications. These materials demonstrated efficient interfacial charge transfer, led to the development of photoresponsive devices, broadband photodetectors and chemiresistive sensors, showcasing the real-world potential of the materials.
4) Discovering unique property and functions related to (opto)electronics and electrochemical energy storage/conversion devices as power sources. In the project, we also develop the electrochemical functionalities of these frameworks. Several systems showed high pseudocapacitance, catalytic activity for HER/NRR, and stability in wide potential windows, indicating their promise for energy storage and conversion. We discovered that structural parameters such as interlayer coupling and ligand planarity critically influence these properties, leading to a more nuanced understanding of 2D material design.
Our results have been widely disseminated through over 60 peer-reviewed publications. We presented our findings at international conferences, delivered invited talks, and co-organized workshops to promote interdisciplinary collaboration. The methodologies, materials, and concepts have already been adopted by research groups across Europe, Asia, and North America.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

At the outset of FC2DMOF, the field of 2D conjugated metal–organic frameworks (c-MOFs) was in its infancy, limited to powders or polycrystalline films with modest conductivity and unclear electronic behavior. Our research made significant strides in pushing this field far beyond the state of the art, both in terms of fundamental understanding and practical application.
One of the most important advances was the development of interfacial synthesis techniques including on-water surface growth and surfactant-assisted assembly that allowed for the fabrication of large-area, crystalline, and oriented thin films of 2D c-MOFs. These methods enabled unprecedented control over film morphology, thickness, and domain orientation, creating materials suitable for systematic study and device integration. At the time, no such reproducible and scalable methods existed for producing high quality conductive MOF films.
In terms of materials design, we successfully introduced a family of phthalocyanine 2D conjugated materials that showed remarkably high intrinsic charge carrier mobilities, even exhibiting band-like charge transport, a key point for the integration into optoelectronic devices. These materials broke long-standing assumptions about electronic limitations and opened the door for their use in photodetectors, transistors, and memory elements.
We extended the application scope of 2D c-MOFs beyond what we originally envisioned. The materials developed were successfully applied to electrocatalysis (e.g. HER, NRR, CO2RR), chemiresistive sensing, energy storage. These were not just proof-of-concept demonstrations; in many cases, the performance of our MOFs matched or exceeded existing benchmark materials, establishing their relevance in next-generation technologies.
Scientifically, we revealed structure–function relationships in these materials at near-atomic resolution, incl. the critical role of interlayer distance, stacking mode, and kind of coordination linkages. This has significantly deepened the understanding of 2D conductive frameworks now being cited and extended by groups worldwide.
In the end, we exceeded our original goals. We generated over 60 publications, established a strong international collaboration network, trained a new cohort of interdisciplinary researchers, and laid the foundation for a sustainable and independent research group.
FC2DMOF has thus had a lasting impact not only on our own scientific trajectory but on the broader evolution of the field of 2D functional materials.

Picture of PI Renhao Dong