Synergistic effect of oxygen vacancies and Ni particles over the ZnWO 4 /CdS heterostructure for enhanced photocatalytic reduction and oxidation activities

• Published in: Catalysis science & technology 2023-02, Vol.13 (4), p.1196-1207
• Main Authors: Zhang, Houfeng, Gan, Shenglong, Hou, Dongfang, Qiao, Xiu-qing, Chi, Ruan, Li, Dong-Sheng
• Format: Article
• Language: English
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/D2CY01872A

Optimization of charge-transfer pathway is of great significance in a capable photocatalytic system with a heterostructure for ensuring excellent reducibility and oxidizability. Herein, we synthesized well-built photocatalysts of oxygen vacancy decorated ZnWO 4 (Vo-ZnWO 4 ) nanorods coupled with CdS microspheres and Ni particles via a hydrothermal and photochemical deposition method, which may result in a change in the interface charge-transfer pathway from the traditional type-II to the Z-scheme mechanism. The Vo-ZnWO 4 /CdS–Ni Z-scheme heterojunction presented significant enhancements in photocatalytic activities and stability for H 2 evolution, and the rate was up to 22.84 mmol g −1 h −1 , approximately 2284 and 7 times higher than those of pure Vo-ZnWO 4 and CdS, respectively. In addition, it showed excellent activities in the photocatalytic reduction of CO 2 and in the oxidative degradation of tetracycline (TC) under visible-light irradiation. Benefiting from the introduction of oxygen vacancies and Ni particles with the dual function of an electron medium and cocatalyst, a feasible and efficient Z-scheme band alignment was constructed to steer the carriers in a predictable direction, addressing two major issues associated with the poor activity and stability. This work could appeal to researchers in designing an effective strategy to carry out multi-directional modification for enhancing photocatalytic reduction and oxidation activities.