2D/3D BiVO<sub>4</sub>@ZnIn<sub>2</sub>S<sub>4</sub> Hierarchical Heterojunction for Enhanced One-Electron Oxygen Reduction Kinetics of H<sub>2</sub>O<sub>2</sub> Artificial Photosynthesis
Wanchuan Jin, Xiaoyan Zhong, Xinhua Li, Ke Yang, Sili Liu, Ruishi Xie, Yuanli Li
Abstract
Hydrogen peroxide (H 2 O 2 ) artificial photosynthesis converts low-density solar energy into storable clean chemical energy, which is an important hot topic in green chemistry. Constructing heterojunctions is an effective tactic to enhance the oxygen reduction kinetics of H 2 O 2 photosynthesis, however, the actual source of activity remains ambiguous. Here, a series of BiVO 4 @ZnIn 2 S 4 hierarchical heterojunctions (BZ- x, x = 0.4, 0.8, 1.2) were elegantly designed through piecing two-dimensional (2D) BiVO 4 nanosheets onto the surface of three-dimensional (3D) ZnIn 2 S 4 flower-like microspheres by a straightforward ethanol ultrasound-induced self-assembly strategy. These BZ- x photocatalysts exhibit significantly enhanced photocatalytic H 2 O 2 production rates across a wide pH range (3–13) compared with those of pristine BiVO 4 and ZnIn 2 S 4, with the optimal BZ-0.8 showing an excellent photocatalytic H 2 O 2 production rate as high as 1585.99 μmol g –1 h –1 . Comprehensive analysis reveals that 2D BiVO 4 nanosheets and 3D ZnIn 2 S 4 flower-like microspheres form a Z-scheme hierarchical heterojunction, which can deliver a favorable energy coupling between photogenerated electrons and the chemical adsorption of O 2 at the interface of hierarchical heterojunctions, thereby accelerating the two-step one-electron kinetic process. This study provides a new perspective for improving photocatalytic H 2 O 2 production by introducing hierarchical heterojunction strategies.