MnFe2O4 nanoparticles coated on one-dimensional carbon nanowires derived from Nitrilotriacetic acid as efficient catalysts to activate peroxymonosulfate for moxifloxacin degradation

Abstract

Sulfate radical-based advanced oxidation processes (AOPs) are highly reliable for the elimination of recalcitrant contaminants by increasing degradability and reducing toxicity. Here, MnFe2O4 nanowires (MnFe2O4 NWs), composed of abundant MnFe2O4 nanoparticles immobilized on one-dimensional carbon nanowires derived from annealed MnFe-Nitrilotriacetic acid (MnFe-NTA) precursor was successfully synthesized. The MnFe2O4 NWs, which could provide more active sites, were then utilized to activate peroxymonosulfate (PMS) for oxidizing the target pollutant Moxifloxacin (MOX) in an aqueous solution. The MnFe2O4 NWs/PMS system acquired 91.9% removal of MOX and achieved 55.1% chemical oxygen demand (COD) degradation efficiency in 30 min. The results exhibited that the increased catalyst doses and PMS concentration lead to ascending MOX removal rate, which decreased with the participation of co-existing ions. Besides, there is a close relationship between original pH and MOX degradation efficiency. It was found that SO4⋅–, ⋅OH, 1O2, and O2⋅– were involved in the MOX degradation by quenching experiments and electron paramagnetic resonance (EPR) detection. More importantly, the stable magnetism of MnFe2O4 NWs contributed to its convenient recycling. Finally, a reliable mechanism for activating PMS was proposed based on the aforementioned results and previous researches, which could exhibit a novel horizon in effluent treatment.