Study on the electrocatalytic degradation of 4-chlorophenol on PbO2–ZrO2 composite electrode and its electrochemical property

PbO2–ZrO2 composite electrodes were prepared by anodic electrodeposition in the lead nitrate solution. The electrochemical property of this electrode was studied by cyclic voltammetry, polarization curves and open-circuit potential–time curves. The results show that PbO2–ZrO2 composite electrodes possess higher oxygen evolution overpotential and better anti-corrosion performance than traditional PbO2 electrodes. Electrocatalytic oxidation of 4-chlorophenol (4-CPs) in aqueous solution was studied to evaluate the applications of this electrode in environmental protection. The influence of experimental parameters on the COD removal efficiency was studied on PbO2–ZrO2 composite electrodes as a function of the current density, initial concentration of the 4-CPs, initial pH, supporting electrolyte concentration and electrolysis time. The results show that the 4-CPs removal efficiency in 0.1 mol L–1 Na2SO4 solution containing 8 mmol L–1 4-CPs could reach 89.2% with the current density at 200 mA cm–2 and pH value at 6.5 after 4 h. Compared with traditional PbO2 anodes, the PbO2–ZrO2 composite electrodes show higher instantaneous current efficiency with degradation of 4-CPs. The experimental results demonstrate that the PbO2–ZrO2 composite electrodes possess the excellent electrocatalytic activity in refractory pollutants degradation.