Tianyang Chen

All Publications

• A Layered Organic Cathode for High-Energy, Fast-Charging, and Long-Lasting Li-Ion Batteries ACS CENTRAL SCIENCE Chen, T., Banda, H., Wang, J., Oppenheim, J. J., Franceschi, A., Dincac, M. 2024

  View details for DOI 10.1021/acscentsci.3c01478

  View details for Web of Science ID 001162222900001

• High-rate, high-capacity electrochemical energy storage in hydrogen-bonded fused aromatics JOULE Chen, T., Banda, H., Yang, L., Li, J., Zhang, Y., Parenti, R., Dinca, M. 2023; 7 (5): 986-1002

  View details for DOI 10.1016/j.joule.2023.03.011

  View details for Web of Science ID 001137001100001

• Superior Charge Transport in Ni-Diamine Conductive MOFs. Journal of the American Chemical Society Wang, J., Chen, T., Jeon, M., Oppenheim, J. J., Tan, B., Kim, J., Dinca, M. 2024

  Abstract

  Two-dimensional conductive metal-organic frameworks (2D cMOFs) are an emerging class of crystalline van der Waals layered materials with tunable porosity and high electrical conductivity. They have been used in a variety of applications, such as energy storage and conversion, chemiresistive sensing, and quantum information. Although designing new conductive 2D cMOFs and studying their composition/structure-property relationships have attracted significant attention, there are still very few examples of 2D cMOFs that exhibit room-temperature electrical conductivity above 1 S cm-1, the value exhibited by activated carbon, a well-known porous and conductive material that serves in myriad applications. When such high conductivities are achieved, Ni-diamine linkages are often involved, yet Ni-diamine MOFs remain difficult to access. Here, we report two new 2D cMOFs made through ortho-diamine connections: M3(HITT)2 (M = Ni, Cu; HITT = 2,3,7,8,12,13-hexaiminotetraazanaphthotetraphene). The electrical conductivity of Ni3(HITT)2 reaches 4.5 S cm-1 at 298 K, whereas the conductivity of Cu3(HITT)2 spans from 0.05 (2Cu+Cu2+) to 10-6 (3Cu2+) upon air oxidation, much lower than that of Ni3(HITT)2. Spectroscopic analysis reveals that Ni3(HITT)2 exhibits significantly stronger in-plane pi-d conjugation and higher density of charge carriers compared to Cu3(HITT)2, accounting for the higher electrical conductivity of Ni3(HITT)2. Cu2+/Cu+ mixed valency modulates the energy level and carrier density of Cu3(HITT)2, allowing for a variation of electrical conductivity over 4 orders of magnitude. This work provides a deeper understanding of the influence of metal nodes on electrical conductivity and confirms ortho-diamine linkers as privileged among ligands for 2D cMOFs.

  View details for DOI 10.1021/jacs.4c06935

  View details for PubMedID 39007301

• Arresting dissolution of two-dimensional metal-organic frameworks enables long life in electrochemical devices. Chemical science Dontireddy, G. M., Suman, S. P., Merino-Gardea, J. L., Chen, T., Dou, J. H., Banda, H. 2024; 15 (27): 10416-10424

  Abstract

  Two-dimensional conjugated metal-organic frameworks (2D cMOFs) are emerging as promising materials for electrochemical energy storage (EES). Despite considerable interest, an understanding of their electrochemical stability and the factors contributing to their degradation during cycling is largely lacking. Here we investigate three Cu-based MOFs and report that the dissolution of 2D cMOFs into electrolytes is a prevalent and significant degradation pathway. Several factors, such as the inherent solubility of ligands in electrolyte solvents and the duration of charge-discharge cycling exert a strong influence on the dissolution process. When these factors combine within a MOF, severely limited cycling stability is observed, with dissolution accounting for up to 80% of capacity degradation. Conversely, excellent cycling stability is observed when testing a Cu-MOF with a sparingly soluble ligand within an optimized potential window. Overall, these findings represent essential insights into the electrochemical stability of 2D cMOFs, offering crucial guidelines for their targeted development in EES applications.

  View details for DOI 10.1039/d4sc02699c

  View details for PubMedID 38994412

  View details for PubMedCentralID PMC11234863

• Arresting dissolution of two-dimensional metal-organic frameworks enables long life in electrochemical devices CHEMICAL SCIENCE Dontireddy, G. R., Suman, S., Merino-Gardea, J. L., Chen, T., Dou, J., Banda, H. 2024

  View details for DOI 10.1039/d4sc02699c

  View details for Web of Science ID 001241910300001

• Cooperative Interactions with Water Drive Hysteresis in a Hydrophilic Metal-Organic Framework CHEMISTRY OF MATERIALS Oppenheim, J. J., Ho, C., Alezi, D., Andrews, J. L., Chen, T., Dinakar, B., Paesani, F., Dinca, M. 2024

  View details for DOI 10.1021/acs.chemmater.4c00172

  View details for Web of Science ID 001191252600001

• Enhanced Redox Storage and Diverse Intercalation in Layered Metal Organic Frameworks with a Staggered Stacking Mode ACS ENERGY LETTERS Suman, S., Dontireddy, G. R., Chen, T., Wang, J., Dou, J., Banda, H. 2024

  View details for DOI 10.1021/acsenergylett.4c00544

  View details for Web of Science ID 001187255100001

• Porous lanthanide metal-organic frameworks with metallic conductivity PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Skorupskii, G., Le, K. N., Cordova, D., Yang, L., Chen, T., Hendon, C. H., Arguilla, M. Q., Dinca, M. 2022; 119 (34): e2205127119

  Abstract

  Metallic charge transport and porosity appear almost mutually exclusive. Whereas metals demand large numbers of free carriers and must have minimal impurities and lattice vibrations to avoid charge scattering, the voids in porous materials limit the carrier concentration, provide ample space for impurities, and create more charge-scattering vibrations due to the size and flexibility of the lattice. No microporous material has been conclusively shown to behave as a metal. Here, we demonstrate that single crystals of the porous metal-organic framework Ln1.5(2,3,6,7,10,11-hexaoxytriphenylene) (Ln = La, Nd) are metallic. The materials display the highest room-temperature conductivities of all porous materials, reaching values above 1,000 S/cm. Single crystals of the compounds additionally show clear temperature-deactivated charge transport, a hallmark of a metallic material. Lastly, a structural transition consistent with charge density wave ordering, present only in metals and rare in any materials, provides additional conclusive proof of the metallic nature of the materials. Our results provide an example of a metal with porosity intrinsic to its structure. We anticipate that the combination of porosity and chemical tunability that these materials possess will provide a unique handle toward controlling the unconventional states that lie within them, such as charge density waves that we observed, or perhaps superconductivity.

  View details for DOI 10.1073/pnas.2205127119

  View details for Web of Science ID 001025718500005

  View details for PubMedID 35969747

  View details for PubMedCentralID PMC9407220

• Thousand-fold increase in O2 electroreduction rates with conductive MOFs. ACS central science Mariano, R. G., Wahab, O. J., Rabinowitz, J. A., Oppenheim, J., Chen, T., Unwin, P. R., Dincǎ, M. 2022; 8 (7): 975-982

  Abstract

  Molecular materials must deliver high current densities to be competitive with traditional heterogeneous catalysts. Despite their high density of active sites, it has been unclear why the reported O2 reduction reaction (ORR) activity of molecularly defined conductive metal-organic frameworks (MOFs) have been very low: ca. -1 mA cm-2. Here, we use a combination of gas diffusion electrolyses and nanoelectrochemical measurements to lift multiscale O2 transport limitations and show that the intrinsic electrocatalytic ORR activity of a model 2D conductive MOF, Ni3(HITP)2, has been underestimated by at least 3 orders of magnitude. When it is supported on a gas diffusion electrode (GDE), Ni3(HITP)2 can deliver ORR activities >-150 mA cm-2 and gravimetric H2O2 electrosynthesis rates exceeding or on par with those of prior heterogeneous electrocatalysts. Enforcing the fastest accessible mass transport rates using scanning electrochemical cell microscopy revealed that Ni3(HITP)2 is capable of ORR current densities exceeding -1200 mA cm-2 and at least another 130-fold higher ORR mass activity than has been observed in GDEs. Our results directly implicate precise control over multiscale mass transport to achieve high-current-density electrocatalysis in molecular materials.

  View details for DOI 10.1021/acscentsci.2c00509

  View details for PubMedID 35912352

  View details for PubMedCentralID PMC9336150

• Thousand-fold increase in O-2 electroreduction rates with conductive MOFs ACS CENTRAL SCIENCE Mariano, R. G., Wahab, O. J., Rabinowitz, J. A., Oppenheim, J., Chen, T., Unwin, P. R., Dinca, M. 2022

  View details for DOI 10.1021/acscentsci.2c00509

  View details for Web of Science ID 000826305200001