Physicochemical Characterization of PbO2 Coatings Electrosynthesized from a Methanesulfonate Electrolytic Solution

Abstract

This work investigated how the compositions of an electrolytic solution consisting of lead methanesulfonate (Pb(CH3SO3)2) and methanesulfonic acid (MSA) affect physicochemical properties of the resulting PbO2 coatings. A series of PbO2 coatings were electrodeposited on the Ti/SnO2–Sb substrate from the methanesulfonate electrolytic bath. Phase constituent and surface micromorphology of the PbO2 coatings were characterized with voltammetric analyses. It is found that concentrations of lead methanesulfonate and MSA influence the electrodeposition in a synergistic manner. At a low Pb(CH3SO3)2 concentration, an increased MSA concentration markedly impacts the deposition kinetics primarily due to the accelerated Pb2+ mass transfer, concurrently leading to a high ratio of α-PbO2. Instead, at a high Pb(CH3SO3)2 concentration, the change of MSA concentration only causes insignificant modification on the structural and morphologic features of the PbO2 coatings. Surface morphologic features of the PbO2 coating depend on electrodeposition conditions, and largely determines the electrocatalytic activity; a rectangular and a pyramidal surface morphology promotes surface redox reactions.