Enhanced levofloxacin degradation by hierarchical porous Co3O4 with rich oxygen vacancies activating peroxymonosulfate: Performance and mechanism

Hierarchical porous Co3O4 with rich oxygen vacancies were fabricated by simple biotemplates derivatization method, and largely promoted the efficiency of peroxymonosulfate (PMS) activation to enhance levofloxacin (LVF) degradation by enlarging the specific surface area and introducing rich oxygen vacancy (O-vac). Results shows that hierarchical porous Co3O4 exposed more surface active sites, Co2+ and Ovac as active sites for PMS activation compared with that of bare Co3O4 obtained without biotemplates, giving rise to largely enhancement of catalytic performance, completely degrading 100% of LVF within 12 min by the optimum Co3O4-II. Besides, experimental studies confirmed that SO4 center dot- and electron transfer mechanism mainly contributed to LVF degradation in Co3O4-II/PMS system. The possible LVF degradation pathway was established on the base of the detected intermediates. This study not only improves the fundamental understanding of active sites in morphologically tunable metal oxides via biotemplates derivatization, but also provides guidance for the research and engineering application of peroxymonosulfate based advanced oxidation process in the future.