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 ZnIn2S4 nanosheets, named as CdS@ZnIn2S4-SV (CdS@ZIS-SV), was synthesized through the strategy of constructing core-shell structure and regulating vacancies. The core-shell structure can confine Cd2+ and S2- 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 S2- 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-SV 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. (c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A semiconductor photocatalyst with a core-shell structure and controlled defects was synthesized, resulting in significantly improved performance and stability compared to the original materials. The hydrogen production rate of the synthesized photocatalyst was several times higher than that of the pristine materials. This work provides guidance for the preparation of high-performance photocatalysts with inhibiting photo-corrosion ability.