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

Resumo

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.