Mechanistic Insight into the Synergy between Platinum Single Atom and Cluster Dual Active Sites Boosting Photocatalytic Hydrogen Evolution

Abstract In the energy transition context, the design and synthesis of high‐performance Pt‐based photocatalysts with low Pt content and ultrahigh atom‐utilization efficiency for hydrogen production are essential. Herein, a facile approach for decorating atomically dispersed Pt cocatalysts having single‐atom (SA) and atomic cluster (C) dual active sites on CdS nanorods (Pt SA+C /CdS) via atomic layer deposition is reported. The size of the cocatalyst and the spatial intimacy of the cocatalyst active sites are precisely engineered at the atomic scale. The Pt SA+C /CdS photocatalysts show the optimized photocatalytic hydrogen evolution activity, achieving a reaction rate of 80.4 mmol h −1 g −1 , which is 1.6‐ and 7.3‐fold higher than those of the Pt SA /CdS and Pt NP /CdS photocatalysts, respectively. Thorough characterization and theoretical calculations reveal that the enhanced photocatalytic activity is due to a remarkable synergy between SAs and atomic clusters as dual active sites, which are responsible for water adsorption–dissociation and hydrogen desorption, respectively. A similar synergetic effect is found in a representative Pt/TiO 2 system, indicating the generality of the strategy. This study demonstrates the significance of the synergy between active sites for enhancing the reaction efficiency, opening a new avenue for the rational design of atomically dispersed photocatalysts with high efficiency.