Nanostructured amorphous MnO 2 prepared by reaction of KMnO 4 with triethanolamine

Abstract

Amorphous manganese dioxide is prepared by reaction of potassium permanganate with an organic reductant triethanolamine. The effect of heat-treatment temperature is studied on the characteristics of the materials. Power X-ray diffraction (XRD), scanning electron microscope (SEM) and N 2 adsorption and desorption measurements are employed to investigate crystalline structure, surface morphology, the specific surface area and the pore size distribution. It is found that when the annealing temperature reaches up to 400 °C, the crystalline convert to α-MnO 2 from amorphous MnO 2. The electrochemical characteristics of the prepared MnO 2 powder are characterized by means of cyclic voltammetry (CV), experiments in 1.0 mol L −1 Na 2SO 4 electrolyte. The specific capacitance (SC) value is 251 F g −1 that is obtained from the product annealing at 350 °C at a CV scan rate of 2 mV s −1. And charging–discharging measurement reveals the good stability of the prepared material.