Remarkably enhanced sulfate radical based photo Fenton like degradation of levofloxacin using the reduced mesoporous MnO@MnOx microspheres
Abstract Sulfate radical based advanced oxidation processes (SR AOPs) are promising alternatives to conventional hydroxyl radical AOPs for recalcitrant contaminants elimination in water treatment. Herein, the efficient and fast degradation of antibiotic levofloxacin (LEV) using mesoporous MnO@MnOx microspheres was successfully achieved with peroxymonosulfate (PMS) as an oxidant under simulated sunlight irradiation. Remarkably, MnO@MnOx catalyst achieves 98.1% degradation and 81.4% mineralization of LEV after being irradiated for 30 min, and SO4 OH, O2 and 1O2 species play the imperative role in the SR photo Fenton like oxidation process. Through the reaction intermediates identification, the LEV degradation pathways are speculated. The deterioration of performance is inconspicuous in the cyclic runs with negligible Mn ions leaching. The excellent catalytic activity and stability of the H2 reduced MnO@MnOx microsphere are ascribed to the mesoporous structure, multivalence and oxygen vacancies, resulting in the large specific area, strong UV vis response, effective charge separation coupling with desirable self redox properties of Mn ions on the catalyst surface. This study offers a useful guideline to efficiently degrade recalcitrant contaminants for water treatment.