Chalcogenide-based S-scheme heterojunction photocatalysts

Abstract

The unique photocatalytic mechanism of S-scheme heterojunction can be used to study new and efficient photocatalysts. By carefully selecting semiconductors for S-scheme heterojunction photocatalysts, it is possible to reduce the rate of photogenerated carrier recombination and increase the conversion efficiency of light into energy. Chalcogenides are a group of compounds that include sulfides and selenides (e.g., CdS, ZnS, Bi₂S₃, MoS₂, ZnSe, CdSe, and CuSe). Chalcogenides have attracted considerable attention as heterojunction photocatalysts owing to their narrow bandgap, wide light absorption range, and excellent photoreduction properties. This paper presents a thorough analysis of S-scheme heterojunction photocatalysts based on chalcogenides. Following an introduction to the fundamental characteristics and benefits of S-scheme heterojunction photocatalysts, various chalcogenide-based S-scheme heterojunction photocatalyst synthesis techniques are summarized. These photocatalysts are used in numerous significant photocatalytic reactions, including the reduction of carbon dioxide, synthesis of hydrogen peroxide, conversion of organic matter, generation of hydrogen from water, nitrogen fixation, degradation of organic pollutants, and sterilization. In addition, cutting-edge characterization techniques, including in situ characterization techniques, are discussed to validate the steady and transient states of photocatalysts with an S-scheme heterojunction. Finally, the design and challenges of chalcogenide-based S-scheme heterojunction photocatalysts are explored and recommended in light of state-of-the-art research.