Sulfur‐vacancy‐enriched <scp>ZnIn</scp>₂<scp>S</scp>₄ rods for accelerated photocatalytic degradation of antibiotics via enhanced oxygen activation and charge dynamics

Abstract The removal of persistent antibiotics from wastewater is a critical challenge for sustainable environmental remediation. Photocatalysis offers a promising solution, yet its efficacy is often limited by inefficient structural design and inadequate activation of molecular oxygen (O 2 ). Here, we report a rod‐shaped ZnIn 2 S 4 photocatalyst enriched with strategically engineered sulfur vacancies (Sv‐ZIS) that address these bottlenecks. The introduction of sulfur vacancies narrows the bandgap, enhancing visible‐light absorption and inducing defect levels that facilitate superior charge separation and transfer. These vacancies also boost the adsorption energy and chemisorption of O 2 molecules, thereby catalyzing the production of superoxide radicals (˙O 2 − ) with high efficiency. The rod‐like morphology further augments the adsorption and interaction of tetracycline molecules with reactive oxygen species (ROS), significantly enhancing photocatalytic degradation performance. Sv‐ZIS achieves tetracycline degradation rates nearly fourfold greater than its bulk counterpart (Bulk‐ZnIn 2 S 4 ), underscoring its transformative potential. This work pioneers a novel structural and defect engineering strategy, advancing the development of high‐performance photocatalysts for tackling antibiotic pollutants in wastewater treatment.