Nanocrystalline ruthenium oxide of fine mesoporosity prepared by templating for electrochemical capacitor applications

Hydrous ruthenium-oxide (RuOxHy) particles composed of nanocrystallites of ∼5 nm in size were prepared, using hexagonal self-ordered mesoporous SiO2 (SBA-15) as a template and RuCl3 as the ruthenium precursor. The material has a highly mesoporous structure with a sharp distribution of fine pores of size around 3–4 nm. A high specific capacitance of 954 F g−1 for the RuOxHy in 1 M H2SO4(aq) and a high energy density of 118.9 J g−1 (or 32.7 W h kg−1) were obtained from an electrochemical capacitor made with the material. Rectangular shape of the cyclic voltammetry was observed even increasing the scan rate to about 100 mV s−1.