Chrysotile fiber-supported NiCo2O4 nanoparticles for peroxymonosulfate activation removing norfloxacin: enhancement mechanisms and degradation pathways

Spinel-type metal oxides NiCo2O4 represents a promising catalyst, yet the agglomeration and inadequate exposure of active sites limit their catalytic effectiveness. Herein, this work proposes an effective method of supporting NiCo2O4 nanoparticles on Chrysotile Fiber (CF), focusing on the reinforcement mechanism and degradation pathways. Results indicated that NiCo2O4@CF-90 exhibited exceptional catalytic performance in activating peroxymonosulfate (PMS) for the degradation of norfloxacin (NOR). The reaction rate constant of the NiCo2O4@CF-90 was 3.98–folds higher than that of the NiCo2O4 without CF support. NiCo2O4@CF-90 exhibited an outstanding degradation efficiency of 99.96% for NOR, attributable to a 96.14% contribution from 1O2 radical. Potential degradation pathways of NOR were included defluorination, decarboxylation, and transformations of the piperazine and quinolone moieties. Toxicity assessment confirmed that a significant reduction in the biological toxicity of degradation products. Further analysis indicates that the CF framework provides a large surface area for loading, which prevents the agglomeration of NiCo2O4 nanoparticles and facilitates their uniform dispersion. This increases the density of accessible active sites for PMS activation, thereby enhancing catalytic performance. Overall, this study demonstrates the effectiveness of the CF framework in enhancing the catalytic performance of NiCo2O4, highlighting its potential application in activating PMS for treating antibiotic-polluted water.