Spectrochimica Acta Part A 64 (2006) 296–300
New technique of synthesizing single-walled carbon nanotubes from
ethanol using ﬂuidized-bed over Fe–Mo/MgO catalyst
QiXin Liu, Yan Fang
Beijing Key Lab for Nanophotonics and Nanostructure, Department of Physics, Capital Normal University, Beijing 100037, PR China
Received 12 May 2005; received in revised form 22 June 2005; accepted 9 July 2005
A new technique of synthesizing single-walled carbon nanotubes (SWCNTs) has been developed by means of the catalytic chemical vapor
deposition (CVD) method from ethanol over MgO supported catalyst using ﬂuidized-bed. Ethanol vapor was introduced into the ﬂuidized-bed
from a temperature-controlled bubbler by the ﬂow of Ar without rotary pump. With this technique, the reaction conditions can be controlled
simply. The ﬂuidized-bed was applied as the reactor instead of quartz boats. Ethanol vapor and the powder of catalyst can be mixed with each
other more sufﬁciently. MgO support can be easily removed from SWCNTs by acid solution. Characteristics of as-grown SWCNTs were
presented using Raman spectroscopic and transmission electron microscopy (TEM), revealing that the SWCNTs produced by this method
possess the signiﬁcant quality of being free from amorphous carbons and having uniform diameter.
© 2005 Elsevier B.V. All rights reserved.
Keywords: SWCNTs; Fluidized-bed; Ethanol; Raman
Since the discovery by Iijima and Ichihara , SWC-
NTs have been the subject of focused studies in many ﬁelds
because of their unique physical and chemical properties
and hence remarkable potential  as a new material in a
wide range of applications, such as nanometer-scale elec-
tronics devices , ﬁeld emission transistors , hydrogen
storage devices [5,6], composites [7,8], etc. With this con-
cern, a synthesis technique of SWCNTs with a higher quality,
higher quantity and at a lower cost is an urgent priority at
present. SWCNTs are produced by three main techniques:
arc discharge , laser ablation  and chemical vapor
deposition (CVD) . Arc discharge methods generally pro-
duce large quantities of impure material and puriﬁcation is
hard to perform. Laser ablation is a costly technique because
of expensive laser equipment and high power requirement.
Nowadays, the CVD method appears to be a promising tech-
nique since it has the potential for a large-scale synthesis of
Corresponding author. Tel.: +86 10 68902965; fax: +86 10 68982332.
E-mail address: email@example.com (Y. Fang).
high-quality SWCNTs at relatively low cost [12,13]. Various
carbon-containing molecules, such as methane , acety-
lene , carbon monoxide [16,17], alcohol , etc., can
be used as carbon source in CVD method. The use of ethanol
as the carbon source in the CVD method exhibits remarkable
advantages, the lower reaction temperature and the high-
purity features of the products guarantee an easy possibility
to scale production up at low cost. Furthermore, the reaction
temperature, which is lower than 600
C , ensures that
the technique is easily applicable for the direct growth of
SWCNTs on semiconductor devices .
Raman spectroscopy, which can be used as a powerful
technique for providing high-quality spectra exhibiting ﬁne
structural detail of molecules, has been proved to be a valu-
able tool for characterizing SWCNTs. Information such as
the structure and quality of the SWCNTs can be obtained
from the Raman spectroscopy.
In this paper, the reactor system of synthesizing SWCNTs
by CVD method from ethanol was improved. The ﬂuidized-
bed was applied as the reactor instead of quartz boats, the
ethanol vapor was introduced into the reactor by the ﬂow of
Ar. The improved reactor system offers multiple advantages,
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