Flower-like bentonite-based Co3O4 with oxygen vacancies-rich as highly efficient peroxymonosulfate activator for lomefloxacin hydrochloride degradation

In this work, a flower-like structure and oxygen vacancies (OVs) enriched bentonite-based Co3O4 (Co3O4/Bent) was successfully prepared, and then was applied as a new activator of peroxymonosulfate (PMS) to degrade lomefloxacin hydrochloride (LOMH). The characterization results demonstrated that Co3O4/Bent had a flower-like structure, high Co(Ⅱ)/Co(III) ratio and high OVs content. The optimal composite of Co3O4/Bent held a high catalytic activity in LOMH degradation, and approximately 87.2 % of LOMH (30 mg/L) could be degraded at 60 min by using Co3O4/Bent (0.2 g/L) to activate PMS (3.0 mmol/L). And the quenching experiments revealed that 1O2, ·OH, SO4·- and ·O2− were the active species and 1O2 played a main role in the LOMH degradation process. The possible degradation pathways were revealed based on DFT calculation and LC-MS analysis. This work suggested that the Co3O4/Bent composite was an efficient catalyst to activate PMS to treat LOMH in wastewater.