A review on ZnO-based S-scheme heterojunction photocatalysts

ZnO, a typical photocatalyst, has aroused great attention due to its nontoxicity, biocompatibility, and earth abundance. However, its performance is hindered by insufficient light absorption capacity, limited reduction ability, and fast recombination of photogenerated carriers (PC). To overcome these challenges, the construction of ZnO-based S-scheme heterojunctions has emerged as an effective solution, enabling the simultaneous realization of spatially separated PC and enhanced redox abilities. Given the notable progress in ZnO-based S-scheme heterojunctions, it is crucial to review the current achievements and provide guidance for future development. This paper presents the development and representative characterization methods of S-scheme heterojunctions, outlines the design principles of ZnO-based S-scheme heterojunctions, and exemplifies the applications of ZnO-based S-scheme heterojunctions in environmental remediation, hydrogen evolution, H2O2 production, and CO2 reduction. Finally, the significant challenges and potential improvements for ZnO-based S-scheme heterojunction photocatalysts are proposed.