Abstract
Hydrous, crystalline, binary (Ru-Ti)O 2 ·nH 2 O with compositions equal to the ratios of metallic ions in the precursor solutions are successfully synthesized by a mild hydrothermal process. The maximum utilization of RuO 2 ·nH 2 O (ca. 793 F/g) occurs at the composition of 60 M% TiO 2 ·nH 2 O although phase separation is clearly found for this TiO 2 -enriched binary oxides. The nano-structured architecture with a high BET surface area (ca. 253 m 2 /g) of the hydrothermal-derived (Ru-Ti)O 2 ·nH 2 O with annealing at 200 °C favors the physical adsorption of water and maintains a high water content which is novel and never found before. Due to this novel nanostructure, the annealed (Ru-Ti)O 2 ·nH 2 O synthesized by means of the hydrothermal process exhibits excellent performances (i.e., high utilization of RuO 2 , high power property, and long cycle life) for supercapacitors. © 2006 Elsevier Ltd. All rights reserved.