Dual activation of peroxymonosulfate with FeS₂@Co₃O₄-C catalyst and visible light for the efficient degradation of tetracycline

Antibiotics have garnered global attention as a pressing concern due to their wide spread discharge to the environment and resulting significant threats to both human health and the environment. The Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) technique has already been verified as an effective process for pollutant degradation. Herein, FeS₂@Co₃O₄-C composites, utilizing ZIF-67-derived Co₃O₄-C as the substrate material, were fabricated using a single-step solvothermal technique for the degradation of tetracycline (TC) by activated peroxymonosulfate (PMS) in combination with visible light irradiation. In the FeS₂@Co₃O₄-C/PMS/Vis system, the FeS₂@Co₃O₄-C showed better activation performance than the single chemical activation system or photocatalytic system, with 97.2 % TC removed in 20 min. The FeS₂@Co₃O₄-C composite material was thoroughly investigated employing X-ray diffraction (XRD) for analyzing its crystal structure, transmission electron microscopy (TEM) for detailed structural insights, scanning electron microscopy (SEM) for morphological examination, and X-ray photoelectron spectroscopy (XPS) for the elemental valence states. The quenching experiments, along with EPR test, revealed that the primary active oxygen species consisted of ¹O₂, O₂^·-, and h⁺. The results presented here suggest the impressive stability and recyclability of FeS₂@Co₃O₄-C making it a potential candidate as an efficient catalyst for initiating the activation of PMS in degrading persistent organic pollutants present in water.