Atomically Precise Metal Nanocluster-Mediated Solar Hydrogen Production

Abstract

Atomically precise metal nanoclusters (NCs) stand out within metal nanomaterials due to the distinctive atomic stacking configuration, discrete energy band, quantum confinement effect, and enriched catalytic centers, positioning them as promising substitutes for conventional photosensitizers in solar energy absorption and utilization. However, the light-induced poor stability and ultrashort carrier lifetime of metal NCs as well as the difficulties in modulating charge migration collectively constrain their potential applications in photoredox catalysis. In this work, we conceptually construct the metal NC artificial photosystems by electrostatically self-assembling l-glutathione (GSH)-capped Au₂₅(GSH)₁₈ NCs onto transition metal chalcogenide (TMC) substrates (CdS, Zn_0.5Cd_0.5S, and ZnIn₂S₄) at ambient conditions. Benefiting from the advantageous photosensitization effect of Au₂₅@(GSH)₁₈ NCs, these self-assembled TMCs/Au₂₅@(GSH)₁₈ NC heterostructures exhibit significantly enhanced photocatalytic hydrogen production performance (λ > 420 nm). This universal photoactivity enhancement is predominantly attributed to the suitable energy level alignment between Au₂₅@(GSH)₁₈ NCs and TMCs, which considerably enhances the interfacial charge transfer and effectively extends the carrier lifetime. In addition, the photocatalytic mechanism is determined. This work would spark continued interest in crafting diverse atomically precise metal NC photocatalytic systems toward solar-to-hydrogen energy conversion.