Enhanced activation of peroxymonosulfate by nanomagnetic CoFe2O4-CeO2/g-C3N4 composites as a heterogeneous catalyst for metronidazole degradation

Antibiotic-induced catastrophic pollution has the potential to migrate over vast distances through water, thereby posing a detrimental effect on both humans and the environment. The construction of a highly robust catalyst to activate peroxymonosulfate (PMS) has become a fascinating approach for treating such types of wastewaters. In this study, we have developed CoFe2O4-CeO2/CN 2 O 4-CeO 2 /CN catalysts using an impregnation-hydrothermal and ultrasonication method to efficiently degrade metronidazole (MNZ). The synthesized catalyst materials were analyzed through multiple characterization techniques in order to correlate the material properties and the degradation performance. The degradation trials exhibited that MNZ underwent complete degradation within 40 min in the CoFe2O4-CeO2/CN-2/PMS 2 O 4-CeO 2 /CN-2/PMS system, with a rate constant of 0.1354 min(-1), nearly 5.29 times faster than the CoFe2O4-CeO2/PMS 2 O 4-CeO 2 /PMS (0.0235 min(-1)) under optimal conditions ([catalyst] = 0.5 g/L, [PMS] = 0.5 mM, [MNZ] = 20 mg/L, pH = 6.72). The increased abatement of MNZ in CoFe2O4-CeO2/CN-2/PMS 2 O 4-CeO 2 /CN-2/PMS system could be attributed to the higher surface area of the CoFe2O4-CeO2/CN-2 2 O 4-CeO 2 /CN-2 (75.96 m2/g) 2 /g) catalyst in comparison to the CoFe2O4-CeO2 2 O 4-CeO 2 (53.98 m2/g), 2 /g), which enhances the catalytically active sites and improves the PMS activation reaction. Besides, the impact of several operational variables and influencing anions on MNZ degradation was researched as well. The generation of free radicals was confirmed by radical scavenging analysis and authenticated using electron paramagnetic resonance analysis. The mechanistic analysis established that the activation of PMS was initiated by the transformations of Co3+/Co2+, 3 + /Co 2 + , Fe3+/Fe2+, 3 + /Fe 2 + , and Ce4+/Ce3+. 4 + /Ce 3 + . Briefly, this research provides valuable perspective for future research regarding heterogeneous catalysis leveraging PMS activation to alleviate toxic contaminants.