Band gap engineered chalcogenide nanomaterials for visible light-induced photocatalysis

Abstract Photocatalytic technology is a new type of environmental purification and energy conversion technology that has developed vigorously in the past 20 years. Compared with other traditional methods of pollution control, photocatalytic technology can not only make full use of abundant solar energy, but also have a relatively stable and efficient oxidation capacity without secondary pollution. Photocatalysts are usually semiconductors, which can be divided into two categories: element semiconductor and compound semiconductor according to the chemical composition of the material. The element semiconductor mainly concentrates in germanium silicon semiconductor, while compound semiconductors cover binary, ternary, and polynary system. Solar energy as an energy input, photocatalytic reactions can achieve water splitting, reduction of CO2 emissions, and degradation of pollutants. Due to their unique physical and chemical properties, metal chalcogenides are photocatalysts with broad application prospects. Binary metal chalcogenides CdS, In2S3, WS2, MoS2, and ternary metal sulfide ZnIn2S4 can all achieve visible light-induced photocatalysis. Optimization strategies such as structure and morphology control, doped elements, and construction of heterojunctions can adjust the forbidden band width and light absorption range to improve the photocatalytic ability of metal chalcogenides.