Recyclable biomimetic flower membranes for ofloxacin degradation by peroxymonosulfate activation under visible-light

The construction of a novel ofloxacin degradation catalyst coupled with photocatalysis and PMS activation is of great significance for the regeneration of water resources. A ternary metal (Co, Zn and Mo) sulfide heterojunction with biomimetic flower structure was synthesized using the solvent heat method. And then PVDF@CoZnMoSx membranes were synthetised by researched solvent-assisted nanoparticle embedding (SANE) method, which yielded efficient ofloxacian (OFX) degradation (97.1 %) by PMS activation. The effects of actual environment (such as co-exist ions, organic matter, and actual water matrices) on OFX degradation were observed, and PVDF@CoZnMoSx-3 (Zn:Co = 3:1, PCZM3) exhibited good tolerance for these factors and application value in practice. The pathways of OFX degradation were clarified by LC-MS analysis, and T.E.S.T software simulated the toxicity of the intermediates (P1-P20) gained from LC-MS, which substantiated the efficacy and safety of the PCZM3/PMS system in OFX degradation. The reusability and stability analysis displayed that the OFX degradation of PCZM3/PMS system was maintained in 5 consecutive cycles without additional treatment, and a small number of ions (Co, Zn and Mo) were leached during the OFX degradation. Totally, a new strategy was raised to construct multivariate metal sulfide membranes and couple the photocatalysis and PMS activation, which provided new insights for catalyst membranes to optimize performance.