Peroxymonosulfate activation by Co₃O₄/SnO₂ for efficient degradation of ofloxacin under visible light

In this work, Co₃O₄/SnO₂ catalyst was prepared by a one-pot hydrothermal method and applied in the activation of peroxymonosulfate (PMS) for the degradation of the target pollutant ofloxacin (OFX). The results showed that the PMS/Co₃O₄/SnO₂-8% system had a 92% OFX degradation efficiency after 30 min of catalytic reaction, which was 46 times higher than that of PMS/SnO₂ alone, and the degradation efficiency could be maintained in a wide pH range (5–11). In addition, reactive oxygen species quenching experiments and electron spin resonance spectra confirmed that sulfate radicals, superoxide radicals, hydroxyl radicals and singlet oxygen were the dominant active groups. The excellent recyclability and stability of the as-prepared catalyst were confirmed by cycling experiments and characterization results. Finally, a possible degradation pathway of OFX was suggested, and the intermediate toxicity of this system was identified and analyzed by a quantitative structure–activity relationship (QSAR).