Comparative studies on the performance of porous Ti/Sno2-Sb2O3/Pbo2 enhanced by CNT and Bi Co-doped electrodes for methyl orange oxidation

Abstract

Abstract: Three novel, modified PbO2 electrodes with porous titanium as the substrate were successfully prepared by the anodic deposition method. The modified electrodes contained CNT, Bi, or a combination of the two. Their microstructure and electrochemical properties were characterized by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffraction, linear sweep voltammetry and cyclic voltammetry. Further, their electrochemical active surface area was determined, and their capacity to generate hydroxyl radicals and induce electrochemical degradation of methyl orange was studied. Compared with pure PbO2, electrodes with CNT-PbO2, Bi-PbO2, and the Bi-CNT combination had PbO2 films with educed crystal sizes, which increased their specific surface area and active sites for electrochemical reactions. The Bi-CNT-PbO2 electrode had the highest oxygen evolution over potential, while the generation of hydroxyl radical (·OH) and the electro-catalytic degradation of methyl orange were significantly increased with the Bi-CNT electrode. It was demonstrated that this modification can significantly enhance performance in electro-oxidation processes, including degradation compounds. Such improvements can be of importance for the removal of organic pollutants from effluents.