| Electrochemical oxidation is an environment-friendly method for pollutant control, whose popular issue is to prepare a high-performance anode at present. PbO2, a good anode material in electro-catalytic oxidation, has the advantages of good anti-corrosion, high over-potential for oxygen evolution and lower cost. However, in the practical application of electrochemical oxidative method for degradation of contaminants, the stability of general PbO2 anode is still not good. It has been reported that doping some additives can improve the elctrocatalytic properties ofβ-PbO2, showing better application prospect. CeO2 and polytetrafluoroethylene (PTFE) were selected as dopants to modifyβ-PbO2 electrode, and weight loss rates of the anodes under the accelerated electrolysis were carried out to optimize the plating conditions. The physicalchemical properties and electro-catalytic oxidation characteristics of the modified anodes in inorganic or organic aqueous solution were investigated. In order to improve electro-catalytic activity and service life of the modified PbO2, a new bath solution for plating composited nano-PbO2 was also firstly proposed in this study.The experimental results indicated that a dense and even electrode surface coating could be obtained with lower weight loss rate under the following plating conditions: 3 g·L-1 CeO2, the plating solution agitated by magnetic bar with 1300 r·min-1, temperature at 80℃, current density under 30 mA·cm-2, electrodepostion for 2 h. The electrode surface coating also had better stability of nonstoichiometry during the accelerated electrolysis. A comparision in oxygen evolution (OE) reaction behaviors between CeO2-PTFE-PbO2 and PTFE-PbO2 indicated that CeO2 could effectively eliminate the phenomenon of OE potential decrease caused by PTFE doping. Doping CeO2 could enlarge Tafle slope, apparent activation energy of OE reaction, indicating that addition of CeO2 might weaken the activity of OE reaction.The experimental results of 4-CP degradation on the composited anode showed that doping CeO2 could effectively improve the electro-oxidation characteristics of PbO2, reduce energy consumption and enhance the oxidation efficiency by 10% under the same conditions. The appearent kinetic parameter of 4-CP removal and current efficiency on Ti/CeO2-PTFE-PbO2 anode were 12.32×10-3 min-1 and 5.70%, respectively, which were higher than those of Ti/PTFE-PbO2 anode under the same conditions (8.41×10-3 min-1 and 4.35%). On the basis of above results, CeO2 might affect the lifetime of the active intermediate species (?OH, etc.), which was also confirmed by electrochemical impedance spectroscopy (EIS) test. Furthermore, Ti/CeO2-PTFE-PbO2 anode showed good stability during 4-CP degradation at high potential.To further improve the performance of lead dioxide, a new bath solution was developed in this study: Lead acetate 250.0280.0 g·L-1, NaF 2.0 g·L-1, PTFE 6 g·L-1 and CeO2 3 g·L-1, with some suitable amino acid. The surface of PbO2 coating showed honeycomb-like structure. The analytic results of XRD test showed that the size of PbO2 particle was 812 nm, which is benefit to increase active surface area of the electrode. Electrochemical tests showed that the OE over-potential of nano-lead dioxide was higher than that of traditional lead dioxide, which was mainly caused by the changes of the size of PbO2 particle. The results of 4-CP degradation showed that efficiency of 4-CP removal on nano-lead dioxide was significantly higher than that of traditional lead dioxide, and the weight loss rate of the novel lead dioxide electrode was slower than that of the above electrodes. This novel electrode shows a strong potential for future applications.
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