Novel method for the preparation of carbon supported nano-sized amorphous ruthenium oxides for supercapacitors

摘要

Nanostructured amorphous RuO2 center dot xH(2)O/C Composite materials are prepared via a modified sol-gel process using glycolic acid. The glycolate anion, which dissociates from glycolic acid at pH 7, behaves as a stabilizer by adsorbing onto the RuO2 center dot xH(2)O surface, thus resulting in particles with a size of about 2 mm. As evidenced by zeta potential measurements, the surface charge of RuO2 center dot xH(2)O becomes more electronegative as the amount of glycolic acid increases. After heat treatment at 160 oC to remove the stabilizer, RuO2 center dot xH(2)O/C is found to exhibit an amorphous structure. The specific capacitance of RuO2 center dot xH(2)O/C particles (40 wt% Ru) prepared in the presence of glycolic acid (0.3 g L-1) is 462 F g(-1), which is 30% higher than that of the material prepared in the absence of glycolic acid. Both the nanosized particles and the amorphous structure mainly contribute to this increase in the specific capacitance. (c) 2008 Elsevier B.V. All rights reserved.