High-Quality Single-Walled Carbon Nanotubes Synthesized by Floating Catalyst Chemical Vapor Depostion

2008 ◽  
Vol 47-50 ◽  
pp. 746-749 ◽  
Author(s):  
J. Cheng ◽  
Xiao Ping Zou ◽  
Guang Zhu ◽  
Mao Fa Wang ◽  
Yi Su
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Radial Breathing Mode ◽  
Laser Raman Spectroscopy ◽  
High Quality ◽  
Single Walled Carbon ◽  
Laser Raman ◽  
Walled Carbon Nanotubes

High-quality single-walled carbon nanotubes (SWNTs) are a key aspect in the emerging field nanotechnology. Although many approaches have been developed, the research on the synthesis of SWNTs is still needed. In this study, we report the synthesis of high-quality SWNTs by floating catalyst chemical vapor deposition, which employs ferrocene as the catalyst precursors. We obtained massive deposits at low temperature region. The deposits were characterized by scanning electron microscopy, transmission electron microscopy, and visual laser Raman spectroscopy. The Raman spectrum obtained from raw deposits shows clear radial breathing mode at the range from 180cm-1 to 300cm-1 and high-intensity graphite mode at 1577.7cm-1 with a shoulder at 1550.5cm-1, and almost no detectable peak around at 1545cm-1, which is induced by defects, is observed. These results indicate that the deposits are high-quality SWNTs.

scholarly journals Parametric Study of Single-Walled Carbon Nanotubes Using Alcohol Catalytic Chemical Vapor Deposition

2004 ◽  
Vol 858 ◽  
Author(s):  
H. Emrah Unalan ◽  
Manish Chhowalla
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Parametric Study ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Catalytic Chemical Vapor Deposition ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

ABSTRACTSingle-walled carbon nanotubes (SWNTs) were synthesized both in powder form and on substrates using alcohol catalytic chemical vapor deposition method (ACCVD). A detailed parametric study was conducted. As-grown SWNTs were analyzed using transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FE-SEM) and Raman spectroscopy. Nucleation and growth of SWNTs occurred within seconds after introduction of the alcohol vapor. The results show that high quality SWNTs with a narrow diameter distribution without amorphous carbon can be grown using Co acetate catalyst doped with Fe acetate above 750°C. Defective nanotubes were observed at low (450°C) and high (950°C) temperatures with the optimum temperature being 850°C. In brief, our work has taken a step towards optimizing SWNTs growth conditions using ACCVD.

Production of high quality single-walled carbon nanotubes in a nano-agglomerated fluidized bed reactor

2003 ◽  
Vol 785 ◽  
Author(s):  
Qixiang Wang ◽  
Guoqing Ning ◽  
Fei Wei ◽  
Guohua Luo
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Fluidized Bed ◽  
Single Walled Carbon Nanotubes ◽  
Fluidized Bed Reactor ◽  
Hydrogen Gas ◽  
Synthesis Methods ◽  
High Quality ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

ABSTRACTSSingle-walled carbon nanotubes (SWNTs) have attracted much attention due to their unique structural, mechanical, chemical, and electrical properties. Catalytic chemical vapor deposition (CCVD) through decomposition of hydrocarbons is one of the most challenging synthesis methods to produce SWNTs in large scale. In this paper, high quality SWNTs prepared in a nano-agglomerated fluidized bed reactor (NAFBR) was reported. The reactor is a vertical quartz tube with the inner diameter of about 50 mm. Catalysts nanoparticles used for the production of SWNTs were prepared with Fe metal nanoparticles carried on the surface of MgO. About 150g catalysts powders were loaded on the gas distribution grid. The reaction temperature was controlled at not less than 1123 K. The carrier gas of argon was used to maintain turbulent fluidization of the catalysts powders in FBR. The hydrogen gas was used to reduce the catalysts and to synergize the growth of SWNTs with methane. The powder products were spherical agglomerates of SWNTs bundles tangling with the catalysts particles. By optimizing the process parameters of CCVD, the products of SWNTs with the diameter about 0.9 ∼ 1.8 nm were prepared, without any multi-walled carbon nanotubes (MWNTs) or amorphous carbon. The microstructure of SWNTs products were characterized by the methods of high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Raman spectra, etc. The NAFBR is a commercially viable (effective and continuous production at a low cost) process for the production of SWNTs.

Metal Coated Functionalized Single-Walled Carbon Nanotubes for Composites Application

2007 ◽  
Vol 561-565 ◽  
pp. 655-658 ◽  
Author(s):  
Qiang Zeng ◽  
Jennifer Luna ◽  
Y. Bayazitoglu ◽  
Kenneth Wilson ◽  
M. Ashraf Imam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Single Walled Carbon Nanotubes ◽  
Metal Composite ◽  
X Ray ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Metal Composite Materials ◽  
Walled Carbon Nanotubes

This study is considered as a method for producing multifunctional metal composite materials by using Single-walled Carbon Nanotubes (SWNTs). In this research, various metals (Ni, Cu, Ag ) were successfully deposited onto the surface of SWNTs. It has been found that homogenous dispersion and dense nucleation sites are the necessary conditions to form uniform coating on SWNTs. Functionalization has been applied to achieve considerable improvement in the dispersion of purified single-walled carbon nanotubes. A three-step electroless plating approach was used and the coating mechanism is described in the paper. The samples were characterized by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). The application of coated SWNTs in Titanium will be discussed in this paper.

Selective Synthesis of Single-Walled Carbon Nanotubes by Blending Catalysts

2007 ◽  
Author(s):  
Shuhei Inoue ◽  
Takeshi Nakajima ◽  
Kazuya Nomura ◽  
Yoshihiro Kikuchi
Keyword(s):  
Carbon Nanotubes ◽  
Fermi Level ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Diameter Distribution ◽  
Efficient Catalyst ◽  
Single Walled Carbon ◽  
Similar Density ◽  
Walled Carbon Nanotubes ◽  
Diameter Distributions

Single-walled carbon nanotubes are considered the most attractive material and a lot of synthesis processes are developed. Among these synthesis processes chemical vapor deposition processes are considered to be most suitable for macroscopic production. In many CVD processes the alcohol catalytic CVD process can be the best process because it can produce very pure nanotubes without any purification. However, cobalt is essential as a catalyst that makes the flexibility of catalysts restricted. In this paper, our investigation mainly focused on as follows: The efficiency of combined catalysts with/without cobalt. The diameter distributions against catalysts density. The electrical states of catalysts near Fermi level. Consequently, almost all of cobalt containing catalysts worked well, and the diameter distributions were proportional to the particle size. Efficient catalysts had enough states around Fermi level and the cobalt-less efficient catalyst cluster model showed the similar density of state to the cobalt cluster. Thus, noticing to the DOS, other efficient catalysts can be discovered and the diameter distribution will be controllable by adjusting temperature, a catalyst size, and a catalyst combination without any complicated techniques and facilities.

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