Influence of F-Doped β-PbO2 Conductive Ceramic Layer on the Anodic Behavior of 3D Al/Sn Rod Pb-0.75% Ag for Zinc Electrowinning

In this study, a 3D Al/Sn rod Pb-0.75% Ag anode was prepared by continuous extrusion coating technique, and a conductive ceramic layer was formed by anodic oxidation in a fluoride-containing H2SO4 solution. The phase composition and surface microstructure of the oxide layer were examined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), indicating the presence of F-doped beta-PbO2 ceramic layer. The electrocatalytic characteristics and electrochemical stability of the anodes were explored by cyclic voltammetry, anodic polarization curves, electrochemical impedance spectroscopy (EIS) and the accelerated life test in the zinc electrolyte. It was found that the F-doped beta-PbO2 layer has good electrocatalytic activity and corrosion resistance. The fence-like 3D Al/Sn rod Pb-0.75% Ag/F-doped beta-PbO2 anode plate was continuously used in the zinc electrolyte for 15 days; in addition, it was found that compared to the traditional Pb-0.75% Ag anode plate, the ultimate tensile strength improved by about 31.45%, the average cell voltage decreased by 53 mV, and the output of zinc increased by 3.09%, confirming its feasibility in practical applications for zinc EW. (C) 2019 The Electrochemical Society.