Unveiling Cutting‐Edge Advancements in ZnIn ₂ S ₄ ‐Based Heterojunctions for Photocatalysis

ABSTRACT ZnIn 2 S 4 (ZIS) has garnered significant interest in photocatalytic energy conversion and environmental remediation due to its tunable band gap, strong visible‐light response, and facile synthesis. However, its practical application is severely hindered by inherent limitations, including low charge carrier separation efficiency and sluggish surface reaction kinetics. Constructing heterojunctions has emerged as an effective strategy to enhance ZIS performance by leveraging precise band alignment and interface engineering to optimize charge separation. While excellent reviews on ZIS‐based photocatalysis have been published, comprehensive reviews focusing specifically on the design and evaluation of ZIS‐based heterojunctions remain scarce. This review systematically summarizes recent advances in ZIS‐based heterojunctions, providing a detailed discussion of heterojunction types and key synthesis strategies. Multi‐scale modification strategies for synergistically enhancing photocatalytic activity are also examined. Furthermore, the charge separation mechanisms and surface reaction pathways are elucidated through advanced in situ characterization techniques and density functional theory (DFT) calculations. ZIS‐based heterojunctions demonstrate great potential across various photocatalytic applications, including H 2 evolution, CO 2 reduction, H 2 O 2 production, N 2 fixation, pollutant degradation, and emerging fields such as plastic reforming and tumor therapy. Finally, future research directions are outlined, encompassing crystal phase regulation, adaptive heterojunction design, and AI‐driven screening, thereby providing theoretical guidance for the development of highly efficient ZIS‐based photocatalysts.