Interface‐Engineered TiO 2 /ZnIn 2 S 4 Heterojunction for Enhanced Visible‐Light Photocatalytic Degradation of Rhodamine B

ABSTRACT Rhodamine B (RhB) in wastewater poses serious risks to aquatic ecosystems. Herein, using Tetrabutyltitanate (TTIP) as the crosslinking agent, the Ti‐O‐Zn interface bonds were intentionally constructed through the solvothermal‐calcination method. The interface electronic structure was regulated through interface engineering to achieve efficient charge separation and stable degradation. ZnIn 2 S 4 nanosheets were assembled with TiO 2 nanoparticles to form intimate contacts, and XPS analysis suggests the formation of interfacial Ti‐O‐Zn bonding interactions. These interactions are proposed to act as atomic‐scale charge‐transfer bridges, directionally steering photogenerated electrons from ZnIn 2 S 4 to TiO 2 , which effectively suppresses bulk carrier recombination. Under visible light, the optimized composite achieved 95.7% RhB removal within 60 min based on UV–vis analysis, and its apparent rate constant (0.0523 min −1 ) was 13.1 times that of pure TiO 2 and 5.6 times that of ZnIn 2 S 4 . Radical trapping experiments revealed that ·O 2 − was the major reactive species, whereas h + was involved in the degradation process to some extent. The hierarchical nanoparticle‐nanosheet structure enhances light utilization and surface accessibility, while the robust interfacial bonding ensures stability, with 92.6% activity retained after five cycles. This work demonstrates that tailoring interfacial chemical environments provides a feasible route to boost carrier separation, photocatalytic efficiency, and durability in visible‐light‐driven systems.