Isolated Ni Atoms for Enhanced Photocatalytic H<sub>2</sub>O<sub>2</sub> Performance with 1.05% Solar-to-Chemical Conversion Efficiency in Pure Water
Cheng Jin, Hao Shen, Jinhe Li, Xinge Guo, Shaosheng Rao, Wenqiang Yang, Qinqin Liu, Zhongti Sun, Juan Yang
Abstract
Photocatalytic hydrogen peroxide (H 2 O 2 ) production encounters a major impediment in its low solar-to-chemical conversion (SCC) efficiency due to undesired H 2 O 2 product decomposition. Herein, an isolated nickel (Ni) atom modification strategy is developed to adjust the thermodynamic process of H 2 O 2 production to address the challenge. Sacrificial experiments and in situ characterization reveal that H 2 O 2 generation occurs via a highly selective indirect two-electron oxygen reduction reaction. The optimized photocatalyst exhibits a remarkable H 2 O 2 production rate of 338.9 μmol g cat –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 O 2 adsorption and barrier-free *OOH conversion, favoring H 2 O 2 release and preventing *H 2 O 2 decomposition. This work showcases efficient H 2 O 2 photosynthesis via d-band manipulation, presenting a fresh perspective for advancing high-efficiency SCC systems.