Halide perovskites for water oxidation photocatalysis: A first-principles study on transition metal-doped CsPbBr₃

Photocatalytic water oxidation (WO), a pivotal and universal half-reaction in photocatalysis, limits the efficiency of photocatalytic reactions involving WO due to its sluggish kinetics. Metal halide perovskites, particularly all-inorganic CsPbBr₃, exhibit promising photophysical properties but suffer from low efficiency for WO and instability in humid environments. Herein, we employed first-principles calculations to investigate the intrinsic properties of cubic-phase CsPbBr₃ for WO photocatalysis. The (001)-PbBr₂ surface was identified as the most thermodynamically stable face under humid conditions, serving as the basis for evaluating the effects of transition metals (Fe, Co, Ni, Cu, and Zn) doping. The density of states, Bader charges, and formation energies of transition metal-doped (001)-PbBr₂ surfaces were calculated to evaluate the structure stability. The water oxidation mechanisms of the pristine and doped (001)-PbBr₂ surface were investigated by calculating the water adsorption energy and analyzing the structural evolution of WO intermediates, revealing that Co and Ni doping can enhance the WO activity on the (001)-PbBr₂ surface. This study provides a theoretical prediction for designing durable and efficient halide perovskite-based photocatalysts for WO photocatalysis.