Mesoscale Morphological Control of Electrodeposited Manganese Dioxide Films

Multilayered films of hybrid manganese dioxide have been synthesised in an anodic pulse deposition study with the addition of phosphotungstic acid, H3PW12O40 (PW) to an acidified MnSO4 solution. These hybrid materials exhibit tuneable layered morphologies, which is not present in material synthesised in the absence of PW. Cyclic voltammetry analyses have been performed in situ on single pulse thin film depositions synthesised in the presence of varying concentrations of PW, where minor amounts of PW improves the cycle stability of the material, however larger concentrations lead to a degradation in material performance. In situ electrochemical analysis shows that the incorporated PW clusters do not affect material activity, however they do play a role in defining both meso- and micro-structure.