Quantum-Corrected Plasmonic Effect of Au₂₅ Clusters Regulates Adsorption Behaviors for Boosted Photocatalytic Overall Water Splitting.

Abstract

Plasmonic-assisted solar-driven photocatalytic water splitting for hydrogen production represents a sustainable strategy for green energy generation. However, conventional plasmonic enhancement via photo-induced electron injection into water molecules faces a key limitation: weak interfacial H₂O adsorption characterized by restriction solely to H-atom-mediated interactions, which severely constrains reaction kinetics. Simultaneously, the novel quantum-corrected plasmonic effect could improve the electron models in optoelectronic device; however, within the domain of photocatalytic water splitting, experimental validations of this effect remain relatively scarce. Here, we harness the quantum-corrected plasmonic effect via Au₂₅ nanocluster incorporation to realize and enhance photocatalytic overall water splitting performance, facilitated by modulated surface adsorption behavior through electron-deficient Au^δ+ active sites originating from the size effect and interband transitions. In this case, the Au^δ+ active sites enhance the antibonding-orbital occupancy of adsorbed Au-O species, accelerating both multipath electron injection and the activation process of water molecules, ultimately facilitating the cleavage of H─O bonds. Consequently, it achieves H₂ and O₂ evolution rates of 1.07 and 0.54 mmol h^-1 under light irradiation with catalyst ZnIn₂S₄-Au₂₅, resolving the long-standing challenge of incomplete overall water splitting for sole Au nanoparticle-decorated photocatalysts, providing a promising strategy for photocatalytic overall water splitting and new insights into designing nanocluster-based photocatalysts.