Affordable PbO2 anode on conductive polymer‑carbon composite substrates for non-heavy duty use

Abstract

Abstract The feasibility of using polymer‑carbon composite material (PCCM) substrate, instead of titanium substrate, for the preparation of PbO2 electrode was explored. The preparation procedure was optimized to maximize the performance of the PbO2 anodes. Our investigation shows that introducing α-PbO2 interlayer could significantly enhance the bonding of the surface β-PbO2 with the substrate. The addition of fluoride ions in the electrodeposition electrolyte could refine the grain size of the β-PbO2, resulting in a dense and smooth surface to enhance the service life of the composite anode. Therefore, the electrode PCCM\α\F−-β-PbO2, which had a α-PbO2 interlayer and a fluoride doped β-PbO2 surface layer, showed the longest accelerating life. The results of experiments also showed that the current density and deposition time significantly affected the surface morphologies of the PbO2 composite electrode. The optimal condition for the deposition of F−-β-PbO2 surface layer was 1 h of operation at 10 mA/cm2 current density, and this condition allowed to offer the electrode with a compact surface to prevent the penetration of caustic electrolyte and an appropriate thickness to avoid the strong internal stress. It was also found that the PCCM\α\F−-β-PbO2 exhibited the same electrocatalytic activity as that of the Ti-substrate counterpart electrode for the electrochemical oxidation of 2,4-dichlorophenol. This study indicates that the PCCM substrate can be used as an alternative substrate for the preparation of affordable PbO2 anode for non-heavy duty applications.