Design and tailoring of the nanotubular arrayed architecture of hydrous RuO2 for next generation supercapacitors

By use of the membrane-templated synthesis route, hydrous RuO2 (RuO2 center dot xH(2)O) nanotubular arrayed electrodes were successfully synthesized by means of the anodic deposition technique. The desired three-dimensional mesoporous architecture of RuO2 center dot xH(2)O nanotubular arrayed electrodes with annealing in air at 200 degrees C for 2 h simultaneously maintained the facility of electrolyte penetration, the ease of proton exchange/ diffusion, and the metallic conductivity of crystalline RuO2, exhibiting unexpectedly ultrahigh power characteristics with its frequency "knee" reaching ca. 4.0-7.8 kHz, 20-40 times better than that of RuO2 single crystalline, arrayed nanorods. The specific power and specific energy of annealed RuO2 center dot xH(2)O nanotubes measured at 0.8 V and 4 kHz is equal to 4320 kW kg(-1) and 7.5 W h kg(-1), respectively, demonstrating the characteristics of next generation supercapacitors.