Atom-Precise Heteroatom Core-Tailoring of Nanoclusters for Enhanced Solar Hydrogen Generation

While core-shell nanomaterials are highly desirable for realizing enhanced optical and catalytic properties, their synthesis with atomic-level control is challenging. Here, the synthesis and crystal structure of [Au12Ag32(SePh)(30)](4-), the first example of selenolated Au-Ag core-shell nanoclusters, comprising a gold icosahedron core trapped in a silver dodecahedron, which is protected by an Ag-12(SePh)(30) shell, is presented. The gold core strongly modifies the overall electronic structure and induces synergistic effects, resulting in high enhancements in the stability and near-infrared-II photoluminescence. The Au12Ag32 and its homometal analog Ag-44, show strong interactions with oxygen vacancies of TiO2, facilitating the interfacial charge transfer for photocatalysis. Indeed, the Au12Ag32/TiO2 exhibits remarkable solar H-2 production (6810 mu mol g(-1) h(-1)), which is approximate to 6.2 and approximate to 37.8 times higher than that of Ag-44/TiO2 and TiO2, respectively. Good stability and recyclability with minimal catalytic activity loss are additional features of Au12Ag32/TiO2. The experimental and computational results reveal that the Au12Ag32 acts as an efficient cocatalyst by possessing a favorable electronic structure that aligns well with the TiO2 bands for the enhanced separation of photoinduced charge carriers due to the relatively negatively charged Au-12 core. These atomistic insights will motivate uncovering of the structure-catalytic activity relationships of other nanoclusters.