Atomically Precise Metal Nanocluster-Mediated Photocatalysis

Atomically precise thiolate-capped metal nanoclusters (NCs), as a recently developed category of metal nanomaterials, show emerging potential in solar energy harvesting and conversion owing to the peculiar atom-stacking mode, quantum confinement effect, and discrete energy band structure. However, the super-short photoexcited charge carrier life span and barren active sites of metal NCs as well as instability retard the photosensitization efficiency in photoredox catalysis. Herein, we conceptually demonstrate the general design of glutathione (GSH)-capped metal NCs/transition metal chalcogenides (TMCs), that is, metal NCs [Agx, Ag31(GSH)19, Ag16(GSH)9, Ag9(GSH)6]/TMC (CdS, Zn0.5Cd0.5S) heterostructures by a ligand-initiated self-assembly route, based on which atomically precise metal NCs are accurately anchored on the TMC substrates under substantial electrostatic interaction. It was unveiled that photoinduced electrons from metal NCs can flow to the TMC substrates and holes migrate in an opposite direction, featuring the quintessential type II charge transport pathway because of the suitable energy level alignment, intimate interfacial integration mode, and boosted charge separation. Given the efficacious interfacial charge migration/separation, metal NCs/TMC heterostructures exhibit significantly boosted photoactivities toward selective organic transformation and solar-to-hydrogen conversion under visible light irradiation. Our work would provide new insights into rationally crafting metal NC-based photosystems and open a promising vista for modulating vectorial charge transfer over metal NCs toward substantial solar-to-chemical energy conversion.