Electrochemical-enhanced nanoscale oxygen-vacancy CuFe2O4 to activate persulfate (E/oxygen-vacancy CuFe2O4/PS) for separation of Ebselen from wastewater.

To enhance the catalytic activity of CuFe₂O₄ on PS, a nanoscale oxygen-vacancy CuFe₂O₄ was prepared by hydrogenation reduction technique to construct an advanced oxidation system of electrochemical-enhanced nanoscale oxygen-vacancy CuFe₂O₄-activated persulfate. Using Ebselen (EBS) as a model pollutant, the degradation efficiency, activation mechanism and degradation pathway were studied. The oxygen-vacancy CuFe₂O₄ was characterized and analysed by FESEM, EDS and XPS. The results show that under the optimal reaction conditions (PS = 0.8 g/L, oxygen-vacancy CuFe₂O₄ = 0.3 g/L, initial pH = 6.5), the removal rate of 20 mg/L EBS can reach 92% after reaction for 60 min, which proves that the formation of oxygen-vacancy changed the catalytic inertness of CuFe₂O₄ on PS. It is speculated that in the E/oxygen-vacancy CuFe₂O₄/PS system, the existence of oxygen holes enhances the electron transfer ability and reducibility of the catalyst, so the oxygen-vacancy CuFe₂O₄ can efficiently activate PS to degrade EBS. The quenching experiments show that both ${\rm SO}_4^{\cdot -}$ SO 4 ⋅ − and $\cdot {\rm OH}$ ⋅ OH are involved in the oxidation reaction as reactive radicals in the system, with ${\rm SO}_4^{\cdot -}$ SO 4 ⋅ − being the main reactive radical. In addition, both dissolved oxygen (DO) and anions in the solution inhibit the oxidative degradation of EBS by oxygen-vacancy CuFe₂O₄/PS system. Through GC-MS detection, a possible degradation pathway is proposed. [ABSTRACT FROM AUTHOR]