Insight into the Co3O4 nanoparticles confined in SiO2 aerogel via peroxymonosulfate activation for enrofloxacin degradation: Performance and mechanism

The confinement effect triggered by nano-confinement systems in the advanced oxidation processes has received extensive attention. In this study, the strategy of constructing stable confined Co 3 O 4 @SiO 2 materials and activating peroxymonosulfate (PMS) was adopted to successfully achieve the efficient removal of enrofloxacin (EON). The removal efficiency of EON by Co 3 O 4 @SiO 2 (0.08 g/L) could reach 99 % at pH 0 of 7 and PMS of 0.2 g/L, and the optimal degradation rate could reach 0.147 min −1 , which was 9.6 times higher than that of the unconfined system. The reaction process was mainly driven by the synergistic interaction between the non-radical 1 O 2 and the interfacial electron transfer network, and the formation of oxygen vacancies within the reaction system accelerated the degradation process. Density functional theory calculations further showed that the confinement effect of SiO 2 aerogel stabilized the Co 3 O 4 nanoparticles, the charge transfer efficiency between Co 3 O 4 @SiO 2 and PMS was optimized, and at the same time, Co 3 O 4 was the key active site for EON degradation. This research can provide an effective strategy for the activation of PMS by SiO 2 aerogel confined structure to remove antibiotic pollutants.