Preparation and characterization of PbO₂ electrodes doped with TiO₂ and its degradation effect on azo dye wastewater

In this paper, P25-TiO₂ doped PbO₂ electrodes based on the Ti/SnO₂-Sb substrate were prepared by the co-deposition method. The XRD results justified that P25 particles have been successfully doped into the pbo₂ layer. The surface morphology of prepared electrodes was examined by scanning electron microscopy. It was found that the doped pbo₂ electrode has a more compact and dense surface with no flaw or crack on it, comparing to those of undoped electrodes. The accelerated life test demonstrated that the doped pbo₂ electrode has a better stability than the undoped one. A significant synergetic effect was observed in the organic degradation test under illumination using the doped pbo₂ electrode, as evidenced by linear scanning voltammetry. Acidic condition (pH < 7) induces a better performance in methyl orange degradation due to a higher adsorption of methyl orange on the TiO₂ surface. All the doped electrodes with different TiO₂ doping levels presented high removal efficiency under irradiation, though the increase in service lifetime was not observed. A TiO₂ doping amount of 5 g.L^-1 is established as the optimal dosage for preparing the electrode for the higher performance in both the accelerated life and the degradation tests.