Enhanced electron transfer for activation of peroxymonosulfate via MoS modified iron-based perovskite.

The increasing use of fluoroquinolone antibiotics, which are found in various environmental media, is a constant threat to ecological safety and human health. In this paper, SrFeO@MoS heterogeneous catalyst was prepared to activate peroxymonosulfate (PMS) for the degradation of levofloxacin (LVO). The characteristics of SrFeO@MoS samples were studied and the optimum conditions for the removal of LVO by SrFeO@MoS/PMS system were investigated. The removal of LVO by the SrFeO@MoS-0.3/PMS system could reach 96.06% within 20 min of reaction. The effect of inorganic anions (SO, Cl, NO and HPO) commonly found in actual water bodies on catalytic reaction was explored. The reusability investigation revealed that the catalyst could still remove 88.06% of LVO within 20 min after four cycles. Moreover, SO, OH and O were identified by Electron Paramagnetic Resonance (EPR) tests and scavenger experiments, where the SO and OH were dominant reactive species. Combining with the XPS characterisation, the activation mechanism of SrFeO@MoS-0.3/PMS was proposed, and the oxygen vacancies and transition metals on the sample surface were active sites of PMS activation. Furthermore, the possible degradation pathways of LVO were well-established based on the detected intermediates.