A method of simultaneously electrodepositing α/β-PbO2 coating materials in methanesulfonic acid and its application in zinc electrowinning

Abstract

In the present work, nucleation mechanism, preparation conditions, performance testing and application simulation of lead dioxide coating materials prepared by electrodeposition from methanesulfonic acid were studied to improve anodic process in zinc electrowinning process. Phase growth and transformation of lead dioxide were analyzed by anodic polarization curves, X-ray powder diffraction, scanning electron microscopy SEM, electrochemical impedance spectroscopy (EIS) and Tafel curves. The selection of temperature ranges was found to cause a quantitative difference in the formation of α/β-PbO2 phases, as it made interval effects on the overpotential that was the primary control condition to affect transfer process, while without changing the reaction mechanism apparently. In this way, the precise conditions of obtaining α- or β-PbO2 phases by varying temperatures was confirmed and samples were selected to be tested in long-period galvanostatic electrolysis, electrode (deposition time-α&β: 2 h&2 h) showed the best physicochemical properties and could effectively extend the lifetime (70.4 h) compared with the traditional lead dioxide electrodes (32.3 h) in zinc electrowinning.