Electrochemical deposition of mesoporous manganese oxide film for supercapacitor using a mixture of two surfactants as templating agent

초록

Abstract. Over recent years, mesoporous materials, which have a large specific surface area and pore volume, have received increasing interest in catalysis, selective separation and electrochemical devices such as batteries, fuel cells and supercapacitors. In addition, transition metal oxide as an electrode material is one of active materials for redox supercapacitors. Among the various transition metal oxides, material based on manganese oxide is promising as a candidate for redox supercapacitor owing to their low cost, high abundance, large theoretical specific capacitance and environmentally-friendly properties. In this work, mesoporous manganese oxide film was electrodeposited on the indium-tin-oxide (ITO)-coated glass from an aqueous solution with 10 mM Mn(Ac)2 as a precursor. To construct a mesoporous structure, a mixture of surfactants was used as a templating agent. Proper amount of mixed surfactants was added to the solution for synthesis of mesoporous films. The electrodeposition was conducted with chronoamperometric method at room temperature. The crystallinity and phase of the prepared manganese oxide were analyzed by X-ray diffraction (XRD) and the mesoporous structure of the synthesized electrodes were carried out by small angle X-ray diffraction (SAXRD). The morphology and the surface properties of the samples were also characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties were investigated by Tafel slope and cyclic voltammetry (CV) in a standard three electrode system using a potentiostat.