Properties of Al-doped titanium based PbO2 electrodes

Abstract:

Al-doped Ti/PbO₂ electrodes were prepared by using anodic deposition from solution containing Al (III) cation. Influence of Al-doping on the physicochemical properties of modified PbO₂ coating electrodes was characterized by surface roughometer, scanning electron microscope (SEM), X-ray diffraction (XRD), linear polarization and electrochemical impedance spectroscopy (EIS) techniques, and accelerated life test. The electrocatalytic oxidation degradation behavior of Al-doping PbO₂ electrodes for phenol simulation wastewater was compared. These results show that PbO₂ coatings with smaller size, uniform and dense surface, lower surface roughness and less nodulation defect are obtained when a certain amount of Al₃₊was added into the electrodeposition solution. Al-doping results in increased oxygen evolution potential, improved charge transfer capacity and enhanced electrocatalytic performance for PbO₂ electrodes. Nevertheless, those properties do not uniformly varied with increase of Al₃₊additive amount. When deposited 3h in the bath solution contain 3mM Al₃₊, the electrode prepared has maximum oxygen evolution potential 2.09 V, excellent electrical conductivity, the best electrocatalytic property and the longest accelerated life of 460 h, which is increased by 100h compared with that of the unmodified electrode. The Al-doped Ti/PbO₂ electrodes show good electrochemical oxidation degradation capacity for phenol simulated wastewater. After treatment 180 min the removal rate of phenol is up to 93.6%, and the maximum removal rate of COD can reach 73.6%.