Loading Pt-Ru Dual Atoms on Oxygen-Vacancy-Rich TiO₂ for Efficient Photocatalytic H₂ Production

The utilization of renewable hydrogen represents a critical pathway for addressing contemporary energy challenges while aligning with global climate mitigation imperatives. Photocatalytic water splitting has emerged as a promising approach for green hydrogen generation, with single-atom catalysts (SACs) demonstrating exceptional catalytic activity and selectivity compared to conventional semiconductor materials, positioning them at the forefront of contemporary photocatalysis research. In this study, platinum (Pt) and ruthenium (Ru) species were introduced as active sites onto defective titanium dioxide (Vo-TNS) nanosheets via the deposition-precipitation method, aiming at photocatalytic hydrogen production. A systematic comparison of the hydrogen evolution rates was performed between monometallic Pt/Vo-TNS and bimetallic Pt-Ru/Vo-TNS catalysts in an aqueous solution, with methanol employed as the sacrificial agent. The optimized Pt-Ru/Vo-TNS catalyst showed remarkable hydrogen evolution activity (2408.61 μmol h^-1 g_cat.^-1), which was 89 times and 1.3 times higher than that of TiO₂ (27.06 μmol h^-1 g_cat.^-1) and Pt/Vo-TNS (1867.35 μmol h^-1 g_cat.^-1) catalysts, respectively. This exceptional performance stems from the atomic-level dispersion of noble metals, which maximizes atomic utilization efficiency while maintaining the intrinsic catalytic superiority of precious metals at minimized loading. This study provides a synthesis method for bimetallic single-atom catalysts.