In-situ construction of CdS@ZIS Z-scheme heterojunction with core-shell structure: Defect engineering, enhance photocatalytic hydrogen evolution and inhibit photo-corrosion

Designing the core-shell structure and controlling defect engineering are desirable for improving the performance and stability of semiconductor photocatalysts. Herein, CdS nanorods covered with ultra-thin ZnIn 2 S 4 nanosheets, named as CdS@ZnIn 2 S 4 -S V (CdS@ZIS-S V ), was synthesized through the strategy of constructing core-shell structure and regulating vacancies. The core-shell structure can confine Cd 2+ and S 2− locally around CdS instead of rapidly diffusing into the solution, thereby inhibiting photo-corrosion. The abundant S vacancies can capture photogenerated electrons and promote the separation of electron-hole pairs, thereby preventing the oxidation of S 2− by the holes. In addition, Z-Scheme heterojunction structure helps the effective separation of electron-hole pairs. Notably, the hydrogen production rate of CdS@ZIS-S V reached 18.06 mmol g −1 h −1 , which was 16.9 and 19.6 times than pristine CdS (1.16 mmol g −1 h −1 ) and ZIS (0.92 mmol g −1 h −1 ), respectively. Photoelectric Characterization (PEC), Scanning Kelvin Probe (SKP), UV–vis diffuse reflectance spectra (UV–Vis DRS), Finite-Difference Time-Domain (FDTD) explain the electron transfer mechanism and the reason for the enhanced photocatalytic activity. This work has guiding significance for the preparation of photo-catalysts with high activity and inhibiting photo-corrosion by adjusting S vacancies. CdS nanorods covered with ultra-thin ZnIn 2 S 4 nanosheets has been synthesized through the strategy of constructing core-shell structure and regulating vacancies to form the heterojunction of CdS@ZIS with S Vacancies. CdS@ZIS-S V has high photocatalytic activity and excellent stability. UV–Vis, SKP, FDTD simulation and PEC explored the photocatalytic mechanism. • Synthesis of CdS@ZIS core-shell structures containing S vacancies by hydrothermal method. • The core-shell structure and S vacancies can inhibit the photocorrosion of CdS and ZIS, respectively. • The charge carrier transfer between CdS and ZIS follows the Z-scheme route. • CdS@ZIS-Sv exhibits excellent photocatalytic activity and cycling stability.