Synthesis Of Single-Wall Carbon Nanotube Via CVD Growth Mechanism
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Date
2011-09
Authors
Liu, Wei Wen
Journal Title
Journal ISSN
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Publisher
Universiti Sains Malaysia
Abstract
Single-wall carbon nanotubes (SWCNTs) have been produced and studied since 1993 by many researchers. One of the challenges is to establish ring addition mechanism for a wide range of reaction temperature. By doing this, the growth mechanism of SWCNTs synthesised from aromatic hydrocarbon can be fully understood. Thus, this became the priority concern of this work. This work was started with the development of a catalyst system which was able to form the highest quality of SWCNTs from decomposition of methane. Response surface methodology (RSM) was applied to optimise the reaction parameters such as reaction temperature, reaction time and reaction gas flow rate. The optimum conditions was determined to be a reaction temperature of 900oC, a reaction time of 59 min and a reaction gas (methane/nitrogen) flow rate of 54 mL/min. The effect of carbon precursors on carbon nanotube (CNT) formation was studied. The results show that the types of carbon precursors greatly affect the quality of CNTs produced. Ring addition mechanism was used to explain the formation of CNTs from benzene. The ring addition mechanism for benzene is different with the growth mechanism of CNTs from methane. Due to this reason, smaller diameter and better quality of SWCNTs was formed from decomposition of methane compared to SWCNTs produced from benzene. Besides, it is also found out that higher percentage of semiconducting CNTs was synthesised from methane compared to benzene.
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Keywords
Synthesis of single-wall carbon nanotube , via CVD growth mechanism