Constructing Two Cu-Modified Organophosphomolybdates from a Nanocluster to a One-Dimensional Chain for Boosted Visible-Light-Driven Hydrogen Production

Photocatalytic decomposition of water to produce hydrogen H₂ is an ideal way to solve energy and environmental problems, and the development of highly efficient polyoxometalate catalysts for photocatalytic hydrogen production has attracted wide attention. Herein, two Cu-modified Strandberg-type organophosphomolybdates were successfully synthesized, [Cu­(C₈H₇N₃)­(H₂O)₂]₂[(C₆H₅PO₃)₂Mo₅O₁₅]·4H₂O (1) and [Cu­(phen)­(H₂O)]­[Cu­(phen)­(H₂O)₂]­[(C₆H₅PO₃)₂Mo₅O₁₅]·2H₂O (2) ([(C₆H₅P)₂Mo₅O₂₁]­Cu₂) (C₈H₇N₃ = 2-(1H-pyrazol-3-yl)­pyridine, phen = 1,10-phenanthroline). Two Strandberg-type organophosphomolybdates can be used for visible-light-driven hydrogen production. Also, compound 2 exhibits an H₂ production rate of 6399 μmol g^–1 h^–1 after 8 h light exposure in the presence of photosensitization agent [Ir­(dtbbpy)­(ppy)₂]­[PF₆] and TEOA. In addition, cyclic tests showed that compound 2 could be recycled four times without a significant reduction in catalytic performance. This work offers fresh insight into the development of novel polyoxometalates for efficient hydrogen evolution.