Cu embedded Co oxides and its fenton-like activity for metronidazole degradation over a wide pH range: Active sites of Cu doped Co3O4 with {112} exposed facet

Cu-Co bimetallic catalysts show excellent performance for metronidazole (MNZ) degradation in a Fenton-like reaction, a near complete conversion was achieved. Cu doped Co3O4 with {1 1 2} exposed facet has proved to promote the oxidation of Co2+ to Co3+ in Cu-CoOx. The surface Cu+ on {1 1 2}-enclosed Co3O4 was identified as the main active species for the reaction and its concentration counts a lot in performance. The Cu+ with raised d-band center under Co-Cu synergistic interaction has boosted the dissociation of H2O2 into & BULL;OH with stronger electron donation to H2O2 and elongated O-O bond. Meanwhile, the accelerated redox process especially for Cu on the {1 1 2} facet of Co3O4 with a faster electron transfer rate also contributed to the excellent performance. The optimization of operational parameters of Co1Cu2 in MNZ removal with investigation of degradation pathway were also thoroughly performed.