A Novel Ti/PbO2 Electrode Preparation And Its Application In Anodic Degradation

Anodic degradation is a promising process for treatment of toxic and biologically refractory wastewater due to its high efficiency, easy operation and environmental compatibility. It is well known that the anodes assemble is the heart of the anodic oxidation process. PbO2 is favored to be an electrode material in view of its low electrical resistivity, good resistance to corrosion, low cost, and high over-potential for oxygen evolution. However, the electro-catalytic activity and stability of recent PbO2 electrodes are poor, and PbO2 coatings can detach from Ti substrates easily, therefore, the industrial application is restricted.The main objective of this work is to improve the performance of PbO2 electrode by adding an interlayer of SnO2 doped with Sb and Ru. The influence of the interlayer on the performance of PbO2 electrodes were studied, and the interlayer preparation parameters were optimized. The physicochemical properties and the electrochemical behavior were also investigated.The preparation parameters of interlayer, including Sb doping ratio, Ru doping ratio, thermo-decomposing temperature and interlayer loading, could affect the performance of PbO2 electrode significantly. The Sb doping ratio of 10%, Ru doping ratio of 2%, thermo-decomposing temperature of 500℃and interlayer loading of 5 g/m2 were determined as the optimal preparation parameters. The novel PbO2 electrode was prepared under optimal parameters. It was constructed of Ti substrate, SnO2-Sb2O5-RuO2 interlayer, a-PbO2 intermediate layer andβ-PbO2 surface layer. It had high oxygen over-potential of 1.8 V. It could reduce COD of phenol from initial 1176 mg/L to 70 mg/L with a CE value of 52.9% at a charge loading of 7 Ah/L under the optimized electro-catalytic condition of pH 11,30℃,100 A/m2,2000 mg/L Na2SO4. Its service life was 59 h under the accelerated life tests conditions of 80℃,4 A/cm2 and 0.5 mol/L H2SO4.