Preparation and Electrochemical Capacitance of Ruthenium Oxide-Titania Nanotube Composite
A well-aligned titania nanotube array grown on titanium sheet was fabricated by an anodization process in hydrofluoric acid-phosphoric acid-ethylene glycol aqueous electrolyte. Electroactive ruthenium oxide was filled into independent titania nanotubes or deposited on the surface of planar titanium sheet by an electrodeposition-oxidation process. Electrochemical capacitances of these well-designed ruthenium oxides were investigated for supercapacitor applications. Accordingly, ruthenium oxide-titania/titanium (RuO2-TiO2/Ti) nanocomposite exhibits a much higher specific capacitance, power and energy density than ruthenium oxide/titanium (RuO2/Ti) in sulphate acid electrolyte. The utilization efficiency of RuO2 is intensively improved by introducing a novel electrode substrate with a nanotube array structure. Such a superior performance of RuO2-TiO2/Ti nanocomposite is ascribed to its highly accessible reaction sites of well-tailored RuO2 on TiO2 nanotubes.
Y. B. Xie et al., "Preparation and Electrochemical Capacitance of Ruthenium Oxide-Titania Nanotube Composite", Materials Science Forum, Vol. 614, pp. 235-241, 2009