Convergent paired electrocatalytic degradation of p-dinitrobenzene by Ti/SnO2-Sb/β-PbO2 anode. A new insight into the electrochemical degradation mechanism

Abstract

In this work, a convergent paired electrochemical method was used for the mineralization of p-dinitrobenzene (p-DNB) over a Ti/SnO2-Sb/β-PbO2 anode. This anode shows high overvoltage for oxygen evolution, long service lifetime and excellent electrocatalytic degradation efficiency. The influence of several operating parameters on the conversion paired electrocatalytic degradation of p-DNB and COD removal efficiency has been examined. The results showed that the degradation and COD removal of p-DNB reached up to 100% and 98%, respectively. The most important part of this study is to propose a novel mechanism for electrochemical degradation of p-DNB. We discovered that both anodic and cathodic reactions are responsible for mineralization of p-DNB. Accordingly, we propose a convergent paired electrocatalytic degradation mechanism based on the reduction of p-DNB at the cathode and oxidation of cathodically generated p-diaminobenzene at the anode surface for electrochemical mineralization of p-DNB.