A novel S-scheme ZnO/Ce-g-C3N5 heterojunctions with enhanced photocatalytic activity

Abstract Creating a high-performance photocatalyst is critical for enhancing the degradation of organic contaminants in wastewater. A novel ZN/Ce-CN heterojunctions, in which ZnO nanoparticles were uniformly deposited on the rare earth metal cerium doped g-C3N5 (Ce-CN) nanosheets, was fabricated in a two-step process (hydrothermal and calcination). The Mott-Schott test revealed S-scheme heterojunctions formed between Ce-CN and ZnO rather than type II. Regarding methylene blue (MB) degradation, the as-prepared heterojunctions demonstrated significantly more photocatalytic activity than Ce-CN and ZnO. The presence of heterojunctions in ZN/Ce-CN improves the separation efficiency of photo-induced e-h+ pairs, resulting in ZN/Ce-CN's superior photocatalytic activity. The primary active species engaged in photocatalytic degradation have been discovered to be h+, •OH, and •O2- based on the research results using electron spin resonance spectra and radical trapping. Furthermore, ZN/Ce-CN had excellent reusability and stability. These results demonstrate the remarkable photocatalytic activity of S-scheme photocatalyst in the degradation of organic contaminants.