Effect of Mechanical Activation on the Electrochemical Behavior of MnO2

Electrochemical behaviour of mechanoactivated β-MnO2 powders has been studied by the method of cyclic voltammetry with a carbon-paste electroactive electrode. Mechanical activation was carried out by dry grinding in an AGO-2 planetary ball mill. It was found that the grinding process results in a mechanochemical effect in the surface layer of the oxide particles: Mn (IV) cations are reduced to Mn (III). Voltammetry test detects that mechanical activation of β-MnO2 leads to a new state, which is characteristic for the γ-modification of manganese dioxide (β-MnO2 γ-MnO2).