Synthesis and capacitive property of δ-MnO2 with large surface area

delta-MnO2 with layered structure is synthesized in a mixed system of KMnO4 and C3H6O (epoxypropane) by a facile low-temperature hydrothermal method at 90 A degrees C for 24 h. The obtained product is characterized by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, and N-2 adsorption-desorption, and its electrochemical property was investigated by cyclic voltammetry method. Experiment results show that the as-synthesized product has a layered structure and a high specific surface area of 188 m(2) g(-1), and C3H6O existing in the reaction system plays a crucial role for the formation of delta-MnO2 particles. Electrochemical characterization indicates that the prepared material exhibits an ideal capacitive behavior with the initial capacitance value of 296 F g(-1) in 1 mol L-1 Na2SO4 aqueous solution at a scan rate of 5 mV s(-1) and good cycling behavior.