Controlling the Nanostructure of RuO[sub 2]/Carbon Nanotube Composites by Gas Annealing

Abstract
We fabricated RuO2/carbonRuO2/carbon nanotube (CNT) composites by coating the CNTs with an amorphous RuOxRuOx layer using metallorganic chemical vapor deposition followed by postannealing at a relatively low temperature of 350°C. It was found that the kind of gas used during the postannealing process should affect the nanostructure of the RuO2/CNTRuO2/CNT composites quite significantly. Starting with a thin RuOxRuOx coating layer, we could obtain relatively uniform-sized spherical and elliptical RuO2RuO2 nanoparticles by using Ar and O2O2 gas, respectively, during the postannealing. The growth behaviors of the RuO2RuO2 nanoparticles could be explained in terms of surface self-diffusion. The surface diffusion process can provides a way to fabricate RuO2/CNTRuO2/CNT nanocomposites with a controllable geometrical shape and size, whose process can be used for diverse applications, such as high-performance supercapacitor electrodes, electrocatalysts, gas sensors, and new electrodevices. © 2004 The Electrochemical Society. All rights reserved.