MOFs-derived CuO–Fe3O4@C with abundant oxygen vacancies and strong Cu–Fe interaction for deep mineralization of bisphenol A

A novel CuO-Fe3O4 encapsulated in the carbon framework with abundant oxygen vacancies (CuO-Fe3O4@C) was successfully prepared by thermal conversion of Cu(OAc)2/Fe-metal organic framework. The as-prepared catalyst exhibited excellent peroxymonosulfate (PMS) activation performance, good recyclability and fast magnetic separation. Under optimal conditions, the added BPA (60 mg/L) could be completely removed by CuO-Fe3O4@C/PMS system within 15 min with the degradation rate constant (k) of 0.32 min-1, being 10.3 and 246.2 times that in CuO/PMS (0.031min-1) and Fe3O4/PMS (0.0013 min-1) system. A deep mineralization rate of BPA (＞80%) was achieved within 60 min. The results demonstrated the synergistic effect of bimetallic clusters, oxygen vacancies and carbon framework was a key benefit for the exposure of more active sites, the electron donor capacity and the mass transfer of substrates, thereby promoting the decomposition of BPA. Capture experiments and EPR indicated that 1O2 was the predominant reactive oxygen species (ROSs). The degradation routes of BPA and the activation mechanism of PMS were proposed. This study offers an opportunity to develop promising MOFs-derived hybrid catalysts with tailored structures and properties for the practical application of SR-AOPs.