Preparation and electrochemical properties of Al/Pb-PANI-WC composite inert anodes

Abstract

In search of a suitable material in place of the Pb-Ag alloy anode used in zinc electrowinning, an Al/Pb-PANI (polyaniline)-WC (tungsten carbide) composite inert anode was prepared on an aluminium alloy by double-pulse electrodeposition of PANI and WC particles with Pb2+ from the bath. Anodic polarization curves, cyclic voltammetry curves and Tafel polarization curves were tested in the solutions of 50 g/L Zn2+ and 150 g/L H2SO4 at 35°C, and the effects of PANI concentrations in the preparation bath on overpotential of oxygen evolution, reversibility of electrode reaction, corrosion potential and corrosion current, surface microstructural features and component distributions of the composite inert anode were investigated. The results show that the composite inert anode obtained in the presence of PANI concentration of 20 g/L possesses higher electrocatalytic activity, lower overpotential of oxygen evolution, better reversibility of electrode reaction and corrosion resistance, uniform microstructures and c...