Metal–Organic Framework-Templated Synthesis of In₂S₃/CoS_x Nanocages for Photocatalytic Removal of Antibiotics

Rational design of a hierarchical core–shell structured photocatalyst is crucial for enhancing the separation and transport efficiency of photogenerated carriers, thereby improving the photocatalytic degradation efficiency. In this study, hollow polyhedral CoS x was first synthesized by utilizing dodecahedral Co-based metal–organic framework (ZIF-67) as a Co source and template, followed by introducing In and S species to fabricate hierarchical core–shell In 2 S 3 /CoS x composites. The resulting In 2 S 3 /CoS x porous hollow heterostructured composites exhibited an accelerated interfacial carrier transfer ratio and enhanced photocatalytic removal performance of tetracycline hydrochloride (TCH). Among them, the optimized sample In 2 S 3 /CoS x -2 (CoIS-2) demonstrated the highest TCH removal rate of 0.0324 min –1, which was 22.8 times higher than that of pristine CoS x and 5.7 times higher than that of pure In 2 S 3, respectively. Moreover, its apparent quantum efficiency reached 4.66% at 420 nm. Electron spin resonance analysis and active substance capture experiments confirmed that superoxide radical ( • O 2 – ) played a predominant role in the reaction system. Furthermore, we investigated the dynamics of photoinduced carriers through a series of photoelectric tests combined with density functional theory calculations. This study provides valuable insights into controllable construction of metal–organic framework-based materials with high photocatalytic degradation efficiency and stability.