Isolated Ni Atoms for Enhanced Photocatalytic H2O2 Performance with 1.05% Solar-to-Chemical Conversion Efficiency in Pure Water

Photocatalytic hydrogen peroxide (H2O2) production encounters a major impediment in its low solar-to-chemical conversion (SCC) efficiency due to undesired H2O2 product decomposition. Herein, an isolated nickel (Ni) atom modification strategy is developed to adjust the thermodynamic process of H2O2 production to address the challenge. Sacrificial experiments and in situ characterization reveal that H2O2 generation occurs via a highly selective indirect two-electron oxygen reduction reaction. The optimized photocatalyst exhibits a remarkable H2O2 production rate of 338.9 μmol gcat–1 h–1 in pure water, representing a 48-fold enhancement. Notably, it attains an impressive SCC efficiency of 1.05%, surpassing that of current state-of-the-art catalysts. Theoretical insights reveal the downshifted d-band center facilitates moderate O2 adsorption and barrier-free *OOH conversion, favoring H2O2 release and preventing *H2O2 decomposition. This work showcases efficient H2O2 photosynthesis via d-band manipulation, presenting a fresh perspective for advancing high-efficiency SCC systems.