Co/N co-doped carbonaceous polyhedron as efficient peroxymonosulfate activator for degradation of organic pollutants: Role of cobalt

In this study, Co/N co-doped polyhedron carbonaceous catalyst ([email protected]) with abundant mesoporous, high graphitization degree and cobalt content was synthesized via the pyrolysis of core–shell MOFs composite ([email protected]). The two cobalt species (Co NPs and Co-Nx) coexisted in [email protected] were unveiled to play different role in PMS activation. Concretely, the Co-Nx served as active sites for 1O2 evolution pathway, while Co NPs greatly improved the graphitization degree and thus enhanced the electron transfer pathway. Owing to the novel structure, the as-prepared [email protected] presented superior catalytic performance upon PMS activation for the removal of several organic pollutants in comparison with the catalysts derived from single MOFs (ZIF-8 and ZIF-67) and the transition metal oxides. Moreover, [email protected] could be recovered by thermal treatment, and the [email protected]/PMS system also showed high resistance to inorganic anions and natural organic matter (NOM). This study reveals the crucial role of cobalt species in regulating the structure of catalyst and determining the PMS activation pathway.