The Synthesis of Single-Walled Carbon Nanotubes by CVD Catalyzed with Mesoporous MCM-41 Powder

Abstract

Carbon nanotubes have attracted extensive interests since their discovery in 1991 because of their extraordinary materials properties. One of the major efforts of current research is to find a method to synthesize high purity defect-free carbon nanotubes in cheaper and better controlled ways. Arc-discharge and laser ablation methods have been the major techniques in the past. However, the large-scale synthesis of carbon nanotubes with controlled conformation, i.e. single-walled or multiwalled structures, remains challenging. In the past few years, chemical vapour deposition (CVD) has been recognized as a promising solution. CVD is a versatile process in which hydrocarbon gas molecules are decomposed to reactive species at elevated temperatures and then grow into carbon nanotubes. The growth of carbon nanotubes can be controlled by the selection of different transition metal catalysts such as Ni, Fe, Co, etc. The synthesis of high purity single-walled nanotubes (SWNTs) or multiwalled nanotubes (MWNTs) has been reported by catalytic CVD method. The selection of different types of catalyst support and hydrocarbon feedstock provides us with more control to the reaction. We report here on the growth of single-walled carbon