Highly efficient activation of peroxymonosulfate by MOF derived CoS2@C for degradation of ciprofloxacin

The cobalt disulfide/carbon composite CoS2@C was successfully synthesized using cobalt metal–organic frameworks (MOFs) with different ligands as templates by pyrolysis method. The as-prepared CoS2@C were applied as catalysts of peroxymonosulfate (PMS) for the degradation of antibiotics. The CoS2@C-3, which was prepared using Co-MOF-74 as self-template, exhibited extraordinarily high activity to PMS, more than 90 % of ciprofloxacin (CIP) was degraded in 10 min with a rate constant of 0.249 min−1. Furthermore, the CoS2@C-3/PMS system demonstrated exceptional resistance to humic acid (HA), significant environmental stability, and a wide range of pH adaptation. The SO4•−, ·OH, and 1O2 induced from heterogeneous and homogeneous activation of PMS were identified as reactive oxygen specieses (ROSs) responsible for oxidation of CIP. In addition, electron transfer and Co(IV) = O also participated in the CIP degradation process. According to the results, a plausible catalytic mechanism for PMS by CoS2@C was elucidated, in which S is crucial to the regeneration of ≡Co(II) in situ. Four potential degradation pathways were proposed after the CIP intermediate products were analysed by HPLC-MS. The findings of this study might offer us some insight into how metal sulfides made from MOFs can be effectively used to eliminate contaminants by activating PMS.