The relation between structural features and electrochemical activity of MnO2 nanoparticles synthesized from a polyol-made Mn3O4 precursor

A simple hybrid synthesis processing method was developed to synthesize γ-MnO₂ nanocrystalline particles. The polyol method was modified by the addition of nitric acid in order to allow the synthesizing of single-phase Mn₃O₄ in a large scale. In the sequence, the acid digestion technique was used to transform Mn₃O₄ into γ-MnO₂. Structural and morphological characterization was carried out by X-ray diffractometry, Infrared and Raman spectroscopy, thermogravimetric analysis, nitrogen adsorption isotherm, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties were investigated by cyclic voltammetry and galvanostatic charge–discharge measurements. The synthesized material exhibits a specific capacitance of 125.1 F?g^?1 at a mass loading of 0.98 mg?cm^?2. The relation between structural features and electrochemical activity is discussed by comparing the synthesized material with commercial electrolytic manganese dioxide.