This present work focused on systematically studying the effect of a porous Ti substrate on the surface structure and electrochemical properties of lead dioxide electrodes prepared by anodic deposition under galvanostatic conditions. Characterization experiments, including scanning electron microscopy (SEM), X-ray diffraction (XRD), linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), accelerated life time testing and a degradation experiment of methylene blue trihydrate were performed to determine the effect of different Ti substrates. Compared with the planar Ti substrate, the results showed that the porous Ti substrate decreased the grain size of lead dioxide and formed a compact and fine surface coating. The electrode had smaller crystalline particles and a more compact structure. The porous Ti/SnO 2 -Sb 2 O 3 /PbO 2 electrode had a higher oxygen evolution overpotential, a larger active surface area and higher electrochemical activity. The lifetime of the porous Ti/SnO 2 -Sb 2 O 3 /PbO 2 electrode (214 h) was 3.69 times higher than that of the planar Ti/SnO 2 -Sb 2 O 3 /PbO 2 electrode (58 h). Moreover, the degradation rate constant of methylene blue trihydrate on the porous Ti substrate lead dioxide electrode (0.03868 min À1 ) was 1.52 times than that of the planar Ti substrate lead dioxide electrode (0.02542 min À1 ). Fig. 1 SEM morphology of cross-sections for (a) porous Ti/SnO 2 -Sb 2 O 3 /PbO 2 electrode (Â500), (b) planar Ti/SnO 2 -Sb 2 O 3 electrode.

a Porous Ti/SnO2-Sb2O3-CNT/PbO2 electrodes were successfully fabricated using thermal decomposition technique and electro-deposition technologies. Characterization experiments including Scanning electron microscopy (SEM), Energydispersive spectroscopy (EDS), X-ray diffraction (XRD), Cyclic voltammertry (CV), Electrochemical Impedance Spectroscopy (EIS) and accelerated life time test was performed to evaluate the effect of CNT-doped SnO2-Sb2O3 intermediate layer on PbO2 electrode. The results showed that CNT could be doped into the SnO2-Sb2O3 intermediate layer by thermal decomposition. Compared with porous Ti/SnO2-Sb2O3 substrate, CNT-doped induced the substrate surface forming a fibrous structure, it means that porous Ti/SnO2-Sb2O3-CNT substrate would provide more active sites for PbO2 deposition and could make a compact and fine surface coating. Besides, the CNT modified electrode had higher active surface area and higher electrochemical activity than without CNT doped. The life of porous Ti/SnO2-Sb2O3-CNT/PbO2 (296h) was 1.38 times as much as that of porous Ti/SnO2-Sb2O3/PbO2 electrode (214h). Electro-catalytic oxidation of phenol in aqueous solution was studied to evaluate the electrochemical oxidation ability in environment science. Porous Ti/SnO2-Sb2O3-CNT/PbO2 electrode displayed not only excellent electro-catalytic performance but also low energy consumption using phenol as a model organic pollutant. The porous Ti/SnO2-Sb2O3-CNT/PbO2 electrode has higher kinetic rate constant and chemical oxygen demand (COD), which is 1.73 and 1.09 times those of the porous Ti/SnO2-Sb2O3/PbO2 electrode, respectively. Moreover, CNT-doped can further increase the hydroxyl radical (·OH) generation capacity. All these results illustrated that porous Ti/SnO2-Sb2O3-CNT/PbO2 electrode for pollutants degradation and had a great potential application.

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Abstract:Three novel, modified PbO