Photocatalytic H<sub><b>2</b></sub>O<sub><b>2</b></sub> Production with >30% Quantum Efficiency via Monovalent Copper Dynamics
Fan Yang, Chengyang Feng, Shouwei Zuo, Qingxiao Wang, Fen Wei, H. Miao, Yuanfu Ren, Dongzhi Liu, Wan‐Lu Li, Sibo Wang, Hassan S. Alqahtani, Yun Hau Ng, Huabin Zhang
Abstract
Photocatalytic O 2 reduction to H 2 O 2 is a green and promising technology with advantages in cost-effectiveness, sustainability, and environmental friendliness, but its efficiency is constrained by limited selectivity for the two-electron oxygen reduction reaction (ORR) pathway. Here, we anchored isolated Cu atoms with tunable oxidation states onto WO 3 as effective active centers to enhance photocatalytic H 2 O 2 production. Due to the charge compensation between single atoms and the support, the oxidation state of Cu species exhibited a loading-dependent transition between +2 and +1 valence. Experimental and theoretical analyses indicate that Cu(I) sites exhibit outstanding O 2 adsorption and activation capabilities, transforming the thermodynamically unfavorable hydrogenation of the *OOH intermediate (the rate-determining step in the two-electron ORR pathway) into an exothermic process, thereby significantly improving selectivity and efficiency. The Cu(I)-SA/WO 3 photocatalyst exhibited a H 2 O 2 production rate of 102 μmol h –1 under visible light irradiation, much higher than other reported photocatalysts. More importantly, it achieves an impressive apparent quantum efficiency of 30% at 420 nm, making a significant breakthrough in this field. This work provides novel perspectives for designing single-atom catalysts for efficient H 2 O 2 synthesis via electronic state modulation.