Preparation of ZrO2-Doped Nb/PbO2 Electrode and Electrocatalytic Performance of Methyl Orange Degradation

The zirconium oxide(ZrO2)-doped niobium based lead oxide(Nb/PbO2) electrode was prepared by electrodeposition.The microstructures and electrochemical properties of Nb/ZrO2+PbO2 electrode were investigated using scanning electron microscopy(SEM), X-ray diffraction(XRD), linear sweep voltammetry, electrochemical impedance spectroscopy and cyclic voltammotry. In addition, the Nb/PbO2 electrode was used as an anode for the electrochemical degradation of methyl orange(MO). Results revealed that the ZrO2 doping made the Nb/PbO2 electrode surface denser and rougher with smaller sized crystal particles, which increased the specific surface area and enhanced the electrocatalytic activity of the electrode. The Nb/ZrO2+PbO2 electrode was mainly composed of β-PbO2 with a small amount of α-PbO2 and ZrO2 formed by codeposition. Accordingly, the Nb/ZrO2+PbO2 electrode possessed higher oxygen-evolution potential, larger adsorption capacity and lower charge-transfer resistance, as well as higher electrocatalytic activity in the degradation of organic materials than the Nb/PbO2 electrode. The MO degradation processes were irreversible and controlled by diffusion