Activation of peroxymonosulfate by ZIF-67-derived Co3O4 for the degradation of tetracycline: Effect of roasting temperature

Abstract

A series of ZIF-67-derived materials have been prepared by stirring and roasting ZIF-67 at different temperatures and used to activate persulfate for oxidation of tetracycline. Compared with Co3O4 and common MOFs (MiL-100-Fe, UiO-66, and ZIF-67), ZIF-67-derived materials exhibit excellent catalytic activity. A 95.06 % removal has been achieved for 20 mg/L tetracycline at a catalyst dosage of 0.6 g/L, PMS dosage of 0.2 g/L. The N2 adsorption/desorption experiment and the SEM analysis show that the large specific surface area favors the full contact between the active sites and the pollutants, and the regular pore structure is conducive to the diffusion and mass transfer of the pollutants. Moreover, XRD, Raman, and XPS studies demonstrate that a suitable calcination temperature can promote the formation of oxygen vacancies and active Co2+, essential for the formation of active oxygen species. The free radical scavenging experiment reveals that ·O2– is the main active species, followed by 1O2. The effects of catalyst dosage, PMS dosage, initial pH, and coexisting ions on tetracycline oxidation are also investigated. Thus, this study provides the theoretical basis and practical evidence for activating PMS as a high-performance catalytic material for the degradation of antibiotics in water.