Pt-Rh Alloy as Highly Efficient Cocatalyst Boosting Photocatalytic Hydrogen Production on TiO₂

Photocatalytic hydrogen evolution has emerged as a promising strategy for the sustainable production of hydrogen energy. Herein, a high-performance Pt-Rh alloy cocatalyst was successfully loaded onto commercial TiO2 (P25) using a solvothermal method. The optimized Pt-Rh alloy-supported P25 catalyst (Pt-Rh/P25) exhibited exceptional photocatalytic hydrogen evolution activity, achieving a remarkable production rate of 23391.0 μmol·g–1·h–1 under simulated solar irradiation. This performance represents significant enhancements of 2.14-, 3.60-, and 377.2-fold compared to the Pt/P25, Rh/P25, and bare P25 catalysts, respectively, outperforming most reported TiO2-based photocatalytic systems to date. The remarkable photocatalytic performance of Pt-Rh/P25 was attributed to its improved light absorption capacity and enhanced utilization efficiency of photogenerated carriers. Theoretical calculation indicated that Pt-Rh/P25 exhibited optimized *H adsorption free energy, which significantly promoted photocatalytic hydrogen production kinetics. This work highlights the beneficial impact of alloy cocatalysts on enhancing photocatalytic hydrogen evolution activity and offers insights into the rational design of high-performance photocatalysts.