Promoted photoelectrocatalytic degradation of BPA with peroxymonosulfate on a MnFe2O4 modified carbon paper cathode

The combination of photoelectrocatalytic (PEC) and sulfate radical (SO4 center dot-)-based advanced oxidation technology (SR-AOP) has been regarded as a promising technology for efficient removal of pollutants by in-situ generated reactive radicals in the field of environmental remediation. Herein, a novel PEC/SR-AOP system was constructed by employing a BiVO4 as photoanode and a MnFe2O4 modified carbon fiber paper (MnFe2O4/CFP) as cathode. The introduction of MnFe2O4 greatly promotes the peroxymonosulfate (PMS) activation of CFP cathode, and the PEC process accelerates the PMS activation of MnFe2O4 for the high-active SO4 center dot- production. As a result, the BiVO4-MnFe2O4/CFP system exhibited remarkably enhanced photoelectrocatalytic performances toward Bisphenol A (BPA) degradation. Nearly 100% of BPA can be degraded after 90 min irradiation under the optimal condition of 1.0 V applied bias and 1 mM PMS addition. The apparent rate constant of BPA degradation over the BiVO4-MnFe2O4/CFP PEC/PMS system is achieved to 0.0596 min(-1). Radical scavenger experiments and electron spin resonance confirmed that the generated center dot OH and SO4 center dot- showed the responsible for BPA degradation during PEC reaction. The results of XPS and LSV tests indicated the favorable redox reaction between MnFe2O4/CFP and PMS, which results in the generation of high active SO4 center dot-. This work provided a promising way to synthesize other novel PEC systems with excellent photoelectrocatalytic performance for environmental pollutants removal.