Substituent Effect to Fine-Tune Energy Levels of Atom-Precise [MoOS3]2- Modified Cu(I) Thiolate Clusters Boosting Recyclable Photocatalysis.

Abstract

The propulsion of photocatalytic hydrogen (H2) production is limited by the rational design and regulation of catalysts with precise structures and excellent activities. In this work, the [MoOS3]2- unit is introduced into the Cu(I) clusters to form a series of atomically-precise Mo(VI)-Cu(I) bimetallic clusters of [Cu6(MoOS3)2(C6H5(CH2)S)2(P(C6H4-R)3)4]·xCH3CN (R = H, CH3, or F), which show high photocatalytic H2 evolution activities and excellent stability. By electron push-pull effects of the surface ligand, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of these Mo(VI)-Cu(I) clusters can be finely tuned, promoting the resultant visible-light-driven H2 evolution performance. Furthermore, Mo(VI)-Cu(I) clusters loaded onto the surface of magnetic Fe3O4 carriers significantly reduced the loss of catalysts in the collection process, efficiently addressing the recycling issues of such small cluster-based catalyst. This work not only highlights a competitively universal approach on the design of high-efficiency cluster photocatalysts for energy conversion, but also makes it feasible to manipulate the catalytic performance of clusters through a rational substituent strategy.