Insight into the Effect of Ta2o5 and Ti4o7 Co-Doping on Electrochemical Properties of Pbo2 Composite Anode

Abstract

In this paper, Ti/Sn-Sb-RuOx/β-PbO2-Ta2O5-Ti4O7 composite anode was prepared by pulsed electrodeposition under the guidance of the calculation of formation energy. The effect of Ta2O5 and Ti4O7 co-doping on microstructure, crystal structure and electrochemical performance of electrodes was systemtically investigated. Compared with original sample, the surface of electrode became flatter and denser with appropriate amount of Ta2O5 and Ti4O7 co-doping. Ti/Sn-Sb-RuOx/β-PbO2-Ta2O5-Ti4O7 composite anode presents higher electrocatalytic activity compared with β-PbO2, which is ascribed to the superior electronic conductivity, for example the oxygen precipitation overpotential decreased from 1.57V of β-PbO2 to 1.52V of Ti/Sn-Sb-RuOx/β-PbO2-Ta2O5-Ti4O7. In addition, Ti/Sn-Sb-RuOx/β-PbO2-Ta2O5-Ti4O7 composite electrodes aslo exhibits longer service life compared with Ti/Sn-SbOx/β-PbO2 (increased by 159% compared with β-PbO2). The improvement on service life is ascribed to the failure mechanism of the modified samples changed from localized preferential corrosion of β-PbO2 to total corrosion, as demonstrated by the SEM result. Furthermore, the enhancement mechanism on electrochemical performance was deeply investigated by the charge densities and electron clouds. This paper may provide theoretical and experimental support for the modification of β-PbO2 anode.

Keywords: β-PbO2, doping, Electrochemical property, Electrocatalytic Activity, Formation Energy.