Converting the Charge Transfer in ZnO/ZnxCd1‐xS‐DETA Nanocomposite from Type‐I to S‐scheme for Efficient Photocatalytic Hydrogen Production

Abstract

Abstract As for the composite photocatalysts, the carrier transfer mechanism at the heterojunction has a very important impact on their photocatalytic performances. In this work, the bandgap of ZnxCd1‐xS‐DETA can be tuned by adjusting the ratio of Cd2+/Zn2+. With the change of the bandgap of ZnxCd1‐xS‐DETA, the carrier transfer mechanism at the ZnO/ZnxCd1‐xS‐DETA heterojunction changes from Type‐I to S‐scheme, and the photocatalytic properties of ZnO/ZnxCd1‐xS‐DETA nanocomposites also change. Among them, the ZnO/Zn0.5Cd0.5S‐DETA nanocomposite has the best photocatalytic hydrogen evolution activity under visible light, and its hydrogen evolution rate is 2.58 mmol g−1 h−1. In addition, after seven cycles, the ZnO/Zn0.5Cd0.5S‐DETA nanocomposite photocatalyst has no significant decrease in hydrogen evolution rate, which is showing its excellent stability. This work reveals that the carrier transfer mechanism at the heterojunction of composite photocatalysts can be changed by the modulation of bandgap, which provides an effective idea for the development of photocatalysts.

Keywords

• Hydrogen energy
• Photocatalysis
• Semiconductor
• S‐scheme