Fe-modified CoS2/ZnIn2S4 heterojunction for dual-driven photoactivation of peroxymonosulfate: Efficient degradation of antibiotics in water

Photocatalysis-coupled advanced oxidation rapidly mineralizes pollutants; here we engineer a Fe-CoS 2 /ZnIn 2 S 4 composite catalyst that activates peroxymonosulfate under visible light to eliminate tetracycline within minutes. The structure, morphology, composition, and optical properties of the photocatalyst were analyzed in detail. Fe-CoS 2 /ZnIn 2 S 4 exhibited markedly improved degradation performance, achieving 88 % TCH removal within 10 min and 94.6 % degradation efficiency within 30 min. The separation and transfer characteristics of photogenerated charges were investigated via surface photovoltage (SPV), transient photovoltage (TPV), photoluminescence (PL) spectroscopy, and UV–visible diffuse reflectance spectroscopy (UV-Vis DRS). Furthermore, the degradation of organic pollutants by sulfate radical-based advanced oxidation processes (SR-AOPs) assisted by photocatalysis was thoroughly studied. The test results demonstrate that the synergistic effects of metal nanoparticle loading and heterojunction construction enable the composite catalyst to achieve efficient photogenerated-carrier separation and rapid Co 3 + /Co 2+ cycling, thereby accelerating PMS activation and generating abundant radicals for pollutant removal. This study offers new insights for developing highly efficient PMS photo-activators for water treatment.