Boosted solar water oxidation steered by atomically precise alloy nanocluster

Atomically precise metal nanoclusters (NCs) have been deemed as a new generation of metal nanomaterials in the field of solar energy conversion due to their unique atomic stacking manner, quantum confinement effects, light-harvesting capability and multitude of active sites. Nonetheless, wide-spread application of monometallic NCs is blocked by the ultrashort carrier lifespan, uncontrollable charge transport pathway, and light-induced poor stability, impeding the construction of robust and stable metal NC-based photosystems. Herein, we report the fabrication of stable alloy (Au_1-xPt_x) NCs photosystem, for which tailor-made negatively charged l-glutathione (GSH)-capped Au_1-xPt_x NCs as the building blocks are controllably deposited on the BiVO₄ (BVO) by a self-assembly approach for steering enhanced light absorption and interfacial charge transfer over alloy NCs-based photoanodes (Au_1-xPt_x/BVO). The self-assembled Au_1-xPt_x/BVO composite photoanode exhibits the significantly enhanced photoelectrochemical water oxidation performances compared with pristine BVO and Au_x/BVO photoanodes, which is caused by the Pt atom doping into the Au_x NCs for elevating photosensitivity and boosting the stability. The synergy of Au and Pt atoms in alloy NCs protects the gold core from rapid oxidation, improving the photostability and accelerating the surface charge transfer kinetics. Our work would significantly inspire ongoing interest in unlocking the charge transport characteristics of atomically precise alloy NCs for solar energy conversion.