Abstract
By use of the membrane-templated synthesis route, hydrous RuO 2 (RuO 2 ·xH 2 O) nanotubular arrayed electrodes were successfully synthesized by means of the anodic deposition technique. The desired three-dimensional mesoporous architecture of RuO 2 · xH 2 O nanotubular arrayed electrodes with annealing in air at 200°C for 2 h simultaneously maintained the facility of electrolyte penetration, the ease of proton exchange/diffusion, and the metallic conductivity of crystalline RuO 2 , exhibiting unexpectedly ultrahigh power characteristics with its frequency "knee" reaching ca. 4.0-7.8 kHz, 20-40 times better than that of RuO 2 single crystalline, arrayed nanorods. The specific power and specific energy of annealed RuO 2 ·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. © 2006 American Chemical Society.