Comparison of the performance and mechanism of NiO/CSs and CuO/CSs in activating peroxymonosulfate for the degradation of levofloxacin.

NiO/Carbon spheres (CSs) and CuO/CSs composites were successfully prepared by a one-step hydrothermal-calcination method. Their performance and mechanisms for activating peroxymonosulfate (PMS) to degrade levofloxacin (LEV) were systematically compared. SEM, TEM, XRD, BET, and FTIR characterization confirmed the successful synthesis and structural features of the materials. The results showed that, under the conditions of 0.6 mmol/L PMS and 0.1 g/L catalyst dosage, NiO/CSs achieved about 78% degradation of LEV within 30 min, while CuO/CSs achieved about 69% degradation under the same conditions. Quenching experiments indicated that ¹O₂, SO₄•⁻, and •OH were the main reactive species in the degradation process. After four reuse cycles, NiO/CSs still maintained a degradation efficiency of 70%, while CuO/CSs maintained 60%, showing good stability. This study compares the catalytic behaviors of NiO/CSs and CuO/CSs in PMS systems and provides experimental support for the design of transition metal oxide/carbon-based composites and their application in antibiotic wastewater treatment.