Influence of the RF Excitation of the Catalyst System on the Morphology of Multiwalled Carbon Nanotubes

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• 作者：Alexandru S. Biris ; Thomas C. Schmitt ; Reginald B. Little ; Zhongrui Li ; Yang Xu ; Alexandru R. Biris ; Dan Lupu ; Enkeleda Dervishi ; Steve Trigwell ; Dwight W. Miller ; Zia Rahman
• 刊名：Journal of Physical Chemistry C
• 出版年：2007
• 出版时间：December 6, 2007
• 年：2007
• 卷：111
• 期：48
• 页码：17970 - 17975
• 全文大小：381K
• 年卷期：v.111,no.48(December 6, 2007)
• ISSN：1932-7455

文摘

Multiwalled carbon nanotubes were synthesized by catalytic chemical vapor deposition using two differentmethods of heating. By one method, an external resistive tube furnace was used, whereas the other methodinvolved heating with radio frequency excitation by induction coil. A comprehensive comparison was madebetween these two methods with regards to feed gas utilization, nanotube growth efficiency, nanotube productcharacterization and morphology, and the formation of amorphous carbon and gaseous byproducts. The carbonnanotubes synthesized using radio frequency excitation exhibited smaller outer diameters, fewer carbon layers,less amorphous carbon, and superior crystalline properties than those produced by external tube furnace. Theradio frequency process resulted in more rapid and sustained growth rates of the nanotubes and more efficientuse of the carbon source. The reason for these enhanced effects by inductive heating may be due not only tothe internally produced thermodynamic heat flow characteristics but perhaps also to induced electron currentsgenerated within the magnetic and metallic catalytic clusters due to RF.