Heterogeneous activation of peroxymonosulfate by recyclable magnetic CuO/Fe3O4 nanosheets for efficient degradation of organic pollutants

Abstract

In this work, recyclable magnetic CuO/Fe3O4 nanosheetswere successfully synthesized via a simple continuous precipitation method, which can effectively activate peroxymonosulfate (PMS) to decompose organic pollutants. The properties of CuO/Fe3O4 nanosheets were measured by a series of characterization techniques. CuO/Fe3O4 composites showed highly effectiveness for PMS activation to degrade methyl blue (MB), and several influencing factors were investigated, such as initial pH, catalyst dosage, PMS concentration and reaction temperature. Although CuO/Fe3O4/PMS system exhibited effectiveness for MB degradation in a wide pH range, the natural pH value was the best. The increase in reaction temperature is favorable for MB degradation, and the activation energy was calculated as 40.34 kJ/mol. Quenching experiments and electron spin resonance (ESR) analysis proved that ·OH, SO4·- and 1O2 were generated in the CuO/Fe3O4/PMS system, and SO4·- and 1O2 played the dominant role. Moreover, CuO/Fe3O4 remained good activity and stability after being recycled five times. In addition, the complete degradation of methylene orange (MO) and tetracycline hydrochloride (TC), and MB degradation in tap water and lake water further confirmed the wide applicability of the CuO/Fe3O4/PMS system. These results exhibited that CuO/Fe3O4/PMS system has great advantages of high removal efficiency, reusability and wide applicability, demonstrating its potential environmental application in the treatment of organic wastewater.