Peroxymonosulfate enhanced photoelectrocatalytic degradation of phenol activated by Co3O4 loaded carbon fiber cathode

In this paper, a photoelectrocatalytic (PEC) system consisting of γ-Bi 2 MoO 6 anode and Co 3 O 4 loaded carbon fiber paper (Co 3 O 4 /CFP) cathode prepared by a hydrothermal method was established and used to degrade phenol . In order to enhance the PEC degradation efficiency of phenol, peroxymonosulfate (PMS) was introduced into this system. At an applied bias of 1.5   V, the removal efficiency of 10   mg/L phenol was increased from 6% to 100% with 2   mM   PMS addition into the PEC process. The degradation rate constant of phenol was also increased to be 0.0496   min −1 . Effects of PMS concentration, applied bias and initial pH were investigated. Based on the ESR analysis, sulfate radicals (SO 4 − ) and hydroxyl radicals (HO ) were proved to be the dominant oxidizing species for phenol degradation in the combined system. The PMS was activated to generate SO 4 − by loaded Co 3 O 4 , in which photogenerated-electrons accelerated the cobalt cycle process on the cathode. As a result, Co leaching was largely inhibited. The stability of the PEC system for organics degradation was exhibited.