Fabrication and characterization of porous titanium-based PbO2 electrode through the pulse electrodeposition method: Deposition condition optimization by orthogonal experiment.

Porous titanium-based PbO2 electrodes were successfully fabricated by pulse electrodeposition method. The primary pulse electrodeposition parameters, including pulse frequency (f), duty ratio (γ), average current density (Ja) and electrodeposition time (t) were considered in this study. An orthogonal experiment was designed based on those four factors and in three levels. SEM images and XRD results suggest that the surface morphology and structure of PbO2 electrodes could be easily changed by varying pulse electrodeposition parameters. Orthogonal analysis reveals that the increase of f and Ja could decrease the average grain size of PbO2 electrodes, which is conducive to create more active sites and promote the generation of hydroxide radicals. The electrochemical degradation of Azophloxine was carried out to evaluate the electrochemical oxidation performance of pulse electrodeposited electrodes. The results indicate that the influences of four factors can be ranked as follow: Ja >γ≈ t > f. The higher f, larger Ja and longer t could facilitate the optimization of the integrated electrochemical degradation performance of prepared PbO2 electrode. The accelerated life time is dominated by Ja and t, coincident with the average weight increase of ß-PbO2 layer. The optimal parameters of pulse electrodeposition turn out to be: f = 50 Hz, γ = 30%, Ja = 25 mA cm-2, t = 60 min. Together, the consequences of the experiments give assistance to uncover and roughly conclude the mechanism of pulse electrodeposition.