Electron Injection from Photoexcited Metal–Organic Framework Ligands to Ru2 Secondary Building Units for Visible-Light-Driven Hydrogen Evolution

We report the design of two new metal–organic frameworks (MOFs), Ru-TBP and Ru-TBP-Zn, based on Ru2 secondary building units (SBUs) and porphyrin-derived tetracarboxylate ligands. The proximity of Ru2 SBUs to porphyrin ligands (∼1.1 nm) facilitates multielectron transfer from excited porphyrins to Ru2 SBUs to enable efficient visible-light-driven hydrogen evolution reaction (HER) in neutral water. Photophysical and electrochemical studies revealed oxidative quenching of excited porphyrin by Ru2 SBUs as the initial step of the HER process and the energetics of key intermediates in the catalytic cycle. Our work provides a new strategy to building multifunctional MOFs with synergistic ligands and SBUs for efficient photocatalysis.

https://pubs.acs.org/doi/abs/10.1021/jacs.8b01601

Guangxu Lan , Yuan-Yuan Zhu†‡Samuel S. VeroneauZiwan Xu†§ , Daniel Micheroni, and Wenbin Lin* 

 Department of Chemistry, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, United States

 School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, China

§ College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China

Adapted with permission from J. Am. Chem. Soc., 2018, 140 (16), pp 5326–5329 Copyright 2018 American Chemical Society.