SYNTHESIS AND CHARACTERISTICS OF CARBON NANOTUBES BY CVD METHOD

Yasushi Soneda

Energy Technology Research Institute,
 National Institute of Advanced Industrial Science and Technology (AIST), 
16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan

During the last decade, possible industrial applications have been anticipated for single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs).  Among many factors, their future usage will strongly depend on the development of new technologies for a large scale production.  The so-called CVD method (catalytic decomposition of hydrocarbons or carbon monoxide disproportionation), which stand on the chemistry of solid-gas reactions on a metallic surface, are the only viable solutions which offer remarkable features of less energy consumption and easy scaling up compared to the other synthesis methods, such as the electric arc discharge or laser ablation of graphite.
In this work, the synthesis of high quality MWCNTs with a significant production rate through acetylene decomposition using iron-group metals supported on MgO is reported.  Compared with other support materials such as silica or alumina, MgO can be easily eliminated from the products with mild treatment of HCl solution.  The catalytic metals and CVD conditions governed the structural characteristics of MWCNTs obtained.  By using the bi-metallic catalyst (Fe, Co with Mo) on MgO, a bundle of SWCNTs was also synthesized.
As the possible applications, the behavior of the synthesized nanotubes as the electrode materials for electrochemical capacitor is discussed.