Persulfate activation by MnCuS nanocomposites for degradation of organic pollutants

MnCuS nanocomposites were prepared by one-pot simple hydrothermal method, the crystallinity and morphology were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission Electron Microscope (TEM), and Brunauer, Emmett and Teller (BET) respectively. Then, the materials were then used to activate persulfate (Na₂S₂O₈) in Orange II degradation. The degradation efficiency of MnCuS with Mn:Cu mole ratio of 1:1 reached 98.2% within 120 min under visible light, which have higher efficiency than other mole ratios of samples or pure MnS and CuS, Furthermore, the nanocomposites also showed good recycling stability performance, and the degradation efficiency could still reach 97.1% even after three degradation cycles. The mechanism of activating Na₂S₂O₈ by MnCuS is proposed as follows: the cycling of active sites of Cu(Ⅰ)/Cu(Ⅱ) and Mn(Ⅱ)/Mn(III) catalyzed Na₂S₂O₈ to produce sulfate radicals (SO₄^•−), which improved the catalytic degradation ability of MnCuS/Na₂S₂O₈/visible light system.