Advancements and challenges in g-C3N4/ZnIn2S4 heterojunction photocatalysts

Abstract

Heterojunction photocatalysts, which consist of two or more semiconductors, have garnered significant attention owing to their extensive benefits, including a broad-spectrum response, efficient carrier separation and migration, as well as robust redox capabilities. Among the myriad of semiconductors, graphitic carbon nitride (g-C₃N₄) and zinc indium sulfide (ZnIn₂S₄) have been extensively researched due to their low toxicity, straightforward and scalable synthesis processes, controllable microstructures, and exceptional chemical stability. Recently, there has been a trend towards integrating these two semiconductors to complement each other's strengths. Consequently, a systematic summary and outlook on g-C₃N₄/ZnIn₂S₄ heterojunction photocatalysts is both urgent and valuable. This review summarizes the advancements in the g-C₃N₄/ZnIn₂S₄ heterojunctions in the last 10 years. We first analyzed the charge-transfer mechanisms in the type-I, type-II, Z-scheme and S-scheme heterojunctions. Then the typical synthesis methods employed for creating g-C₃N₄/ZnIn₂S₄ heterojunctions are introduced. Subsequently, we delve into the regulation strategies for g-C₃N₄/ZnIn₂S₄ heterojunctions, including morphology optimization, heteroatom doping, defect engineering, and the construction of multinary composites. The design concept and superiorities of these strategies are thoroughly discussed. Following this, we systematically showcase the photocatalytic applications of g-C₃N₄/ZnIn₂S₄ heterojunctions, encompassing CO₂ reduction, H₂ evolution, pollutant degradation, H₂O₂ production, biomass conversion, photoelectrochemical sensors, and so forth. Last, we propose the challenges that lie ahead in future research endeavors. This comprehensive review is expected to provide an instructive guideline for rational design and applications of g-C₃N₄/ZnIn₂S₄ heterojunctions.