Preparation of metal organic framework derived materials CoFe2O4@NC and its application for degradation of norfloxacin from aqueous solutions by activated peroxymonosulfate

The metal organic framework derived materials (CoFe2O4@NC) activated peroxymonosulfate (PMS) to degrade Norfloxacin (NOR) owing to the characteristics of high surface area (109.658 m2 g−1) and abundant mesoporous structure. The characterization results demonstrated that the optimal ratio of bimetal and of bimetallic to organic ligands (M/O) had good crystal structure and stability (Fe/Co = 3:1, M/O = 2:1). Moreover, NOR (10 mg L−1) removal of 98.78% was achievable in 60 min with an optimum concentration of PMS (0.32 mM) and dosage of CoFe2O4@NC (0.1 g L−1). The radical quenching results suggested that SO4·-, ·OH and 1O2 functioned in the presence of the system certificated by XPS spectra. The presence of Cl− and CO32−/HCO3− promoted the catalyst reaction. The recoverability revealed high removal efficiency of NOR of 93.55% could still be maintained. Furthermore, four pathways of NOR degradation were proposed, including dehydroxylation, defluorination, quinolone group conversion and piperazine ring transformation, which were attributed to the synergy of reactive oxygen species. The above results highlight that the method is of great significance to the practical application of heterogeneous catalysts in aqueous solutions.