Room temperature synthesis of Mn3O4 nanoparticles: characterization, electrochemical properties and hydrothermal transformation to γ-MnO2 nanorods

Abstract A mild and room temperature route has been developed for the synthesis of Mn 3 O 4 nanoparticles by mixing the aqueous solution of MnSO 4 and Na 2 CO 3 . The Mn 3 O 4 products were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and electrochemical tests. A specific capacitance of 205 F g −1 was obtained for Mn 3 O 4 nanoparticles at a current density of 0.5 A g −1 in 1 M Na 2 SO 4 electrolyte solution. The Mn 3 O 4 nanoparticles exhibited a good rate capability and electrochemical stability. In addition, γ-MnO 2 nanorods were prepared from Mn 3 O 4 nanoparticles by a simple hydrothermal treatment at 120 °C under the acidic condition.