Cryo-Electrochemical Deposition of Gold Single Atoms on G-C₃N₄ for Photoelectrochemical Water Reduction

The pursuit of sustainable energy has intensified the exploration of hydrogen as a clean energy carrier, with photoelectrocatalytic water reduction emerging as a green approach to harness solar energy. Graphitic carbon nitride (g-C₃N₄), recognized for its stability and non-toxicity, presents limitations in photoconversion efficiency due to rapid electron-hole recombination and narrow light absorption range. To address these challenges, herein, a cryo-electrochemical deposition strategy is introduced to synthesize g-C₃N₄ loaded with gold single-atom catalysts (Au₁), enhancing charge separation and light absorption. The atomic dispersion of Au₁ on g-C₃N₄ significantly elevates photoelectrocatalytic hydrogen production, achieving a record yield rate on the Au₁(14.5%)/g-C₃N₄ sample. Density functional theory (DFT) calculations and comprehensive characterizations reveal the role of Au₁ in modulating the electronic structure and improving charge carrier dynamics. The findings underscore the potential of single-atom catalysis in advancing photoelectrocatalytic water reduction systems for solar energy conversion and clean energy production.