Photoredox Catalysis Enabled by Atomically Precise Metal Nanoclusters

Abstract

Atomically precise metal nanoclusters (NCs), distinguished by unique electronic structure, quantum confinement effect, and enriched active sites, have been considered as highly promising photosensitizers for light harvesting and conversion. However, ultra-short carrier lifetime and poor stability of metal NCs remarkably retard their widespread applications in photocatalysis. In this study, we achieve the modulation of carrier separation over metal NCs via heterostructure engineering by smartly integrating atomically precise silver NCs [Ag16(GSH)9] with transition metal chalcogenides (TMCs). It is unleashed that the favorable energy level alignment between metal NCs and TMCs facilitates the electron transfer from the metal NCs to the TMCs, leading to significantly prolonged charge lifetime and considerably enhanced photoactivity toward selective reduction of nitro compounds to amino derivatives under visible light. The photocatalytic mechanism of this composite photosystems is elucidated. This work would advance our fundamental understanding on charge transfer mechanisms over atomically precise metal NCs for solar energy conversion.