Degradation of P-Nitrophenol Affected by Synergy of Indirect and Direct Electrooxidation

The synergy of indirect and direct electrooxidation of p-nitrophenol (PNP) at Ti/PbO2 anode was studied with linear sweeping voltammetry and galvanostatic electrolysis. The concentration of PNP and the form of redox medium were detected by high performance liquid chromatography (HPLC) and ion chromatography. The results indicated that Ti/PbO2 electrode can electrocatalyze the degradation of PNP effectively. The degradation ratio of 1.0 mmol/L PNP is 64.5% after 1 h electrolysis when the temperature is 35°C, the current density is 40 mA•cm-2. When the electrolyte containe 1.0 mmol / L Cl-, the degradation ratio of PNP is 81.0% after 1 h electrolysis under the same conditions. Cl-, ClO-, and ClO3- were detected simultaneously in the electrolyte, and their concentrations showed nonlinear oscillation with electrolysis time. These indicated that Cl- cause indirect electrooxidation of PNP, and the redox medium Cl-/Cl2 has a good reversibility.