scholarly journals Controlling the Crystalline Quality and the Purity of Single-walled Carbon Nanotubes Grown by Catalytic Chemical Vapor Deposition

2013 ◽  
Vol 1515 ◽  
Author(s):  
Hugo Navas ◽  
Matthieu Picher ◽  
Raul Arenal ◽  
Etienne Quesnel ◽  
Eric Anglaret ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Defect Density ◽  
Low Frequency ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Growth Conditions ◽  
Single Walled Carbon ◽  
Frequency Components ◽  
Walled Carbon Nanotubes ◽  
By Products

ABSTRACTIt is frequently observed that as-grown single-walled carbon nanotubes (SWCNTs) contain defects. Controlling the defect density is a key issue for the control of nanotube properties. However, little is known about the influence of the growth conditions on the formation of nanotube defects. In addition, SWCNT samples frequently contain carbonaceous by-products which affect their ensemble properties. Raman spectroscopy is commonly used to characterize both features from the measurement of the defect-induced D band. However, the contribution of each carbonaceous species to the D band is usually not known making it difficult to separately extract the defect density and relative abundance of each. Here, we report on the correlated evolution of the D and G’ bands of SWCNT samples with increasing growth temperature. In the general case, three to four Lorentzian components are required to fit them. Coupled with HRTEM characterization, the low frequency components of the D and G’ can be attributed to the contribution of SWCNTs while high frequency components are associated with defective carbonaceous by-products. The nature of these defective by-products varies with the type of catalysts and with the growth conditions.

scholarly journals Influence of the growth conditions on the defect density of single-walled carbon nanotubes

Carbon ◽  
2012 ◽  
Vol 50 (7) ◽  
pp. 2407-2416 ◽  
Author(s):  
Matthieu Picher ◽  
Hugo Navas ◽  
Raul Arenal ◽  
Etienne Quesnel ◽  
Eric Anglaret ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Defect Density ◽  
Single Walled Carbon Nanotubes ◽  
Growth Conditions ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Study on the detection behavior of defect-rich single-walled carbon nanotubes toward perchlorate

2018 ◽  
Vol 11 (02) ◽  
pp. 1850032
Author(s):  
Yi Chen ◽  
Thuy Hang Nguyen ◽  
Shao Lin Zhang ◽  
Z. Zhang ◽  
Hongyan Yue ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Defect Density ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Deposition Process ◽  
Vapor Flow ◽  
Single Walled Carbon ◽  
Future Design ◽  
Detection Capabilities ◽  
Walled Carbon Nanotubes

Defect-rich single-walled carbon nanotubes (SWCNTs) were prepared by a water vapor flow-assisted chemical vapor deposition process. The correlation between defect density and water flow was quantitively studied using Raman spectrum. The detection capabilities of defective SWCNTs films toward perchlorate anions were investigated. It was found the defect-rich SWCNTs could adsorb more perchlorate anions owing to the strong chemical bonding between anions and defective sites. However, the detective response of defective SWCNTs toward perchlorate was not in compliance with anion adsorption. A tradeoff phenomenon between response and adsorption was found as the defect density of SWCNTs increased. This work is expected to provide a guidance to the future design of SWCNTs based ion detector.

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.

Growth of Single-Walled Carbon Nanotubes from Ceramic Particles by Alcohol Chemical Vapor Deposition

2008 ◽  
Vol 1 (1) ◽  
pp. 014001 ◽  
Author(s):  
Huaping Liu ◽  
Daisuke Takagi ◽  
Hiroshi Ohno ◽  
Shohei Chiashi ◽  
Tomohito Chokan ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Ceramic Particles ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

Low-frequency excitations in single-walled carbon nanotubes

2021 ◽  
Author(s):  
Chiun-Yan Lin ◽  
Cheng-Hsueh Yang ◽  
Chih-Wei Chiu ◽  
Hsien-Ching Chung ◽  
Shih-Yang Lin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Low Frequency ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

DIRECTED GROWTH OF SINGLE-WALLED CARBON NANOTUBES

2002 ◽  
Vol 01 (03n04) ◽  
pp. 197-204 ◽  
Author(s):  
LANCE DELZEIT ◽  
RAMSEY STEVENS ◽  
CATTIEN NGUYEN ◽  
M. MEYYAPPAN
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Horizontal Plane ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Thermal Chemical Vapor Deposition ◽  
Single Walled Carbon ◽  
Directed Growth ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWNTs) are grown by thermal chemical vapor deposition at 900°C using methane. Application of an electric field (0.4 V/μm) in situ during the growth process results in directed growth of SWNTs on a horizontal plane bridging a distance as long as 25 μm. This approach is useful in the fabrication of nanotube based transistors.

Low Temperature Synthesis of Single-Walled Carbon Nanotubes in an Inductively Coupled Plasma Chemical Vapor Deposition System

2008 ◽  
Vol 8 (5) ◽  
pp. 2526-2533 ◽  
Author(s):  
Cheng-Hui Weng ◽  
Chao-Shun Yang ◽  
Hsuan Lin ◽  
Chuen-Horng Tsai ◽  
Keh-Chyang Leou
Keyword(s):  
Carbon Nanotubes ◽  
Low Temperature ◽  
Inductively Coupled Plasma ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Low Temperature Synthesis ◽  
Temperature Synthesis ◽  
Single Walled Carbon ◽  
Inductively Coupled ◽  
Walled Carbon Nanotubes

In this work, we present a parametric study on the low temperature synthesis of single-walled carbon nanotubes (SWNTs) in an inductively coupled plasma (ICP) CVD system using dry bi-layered catalytic thin-films (Fe/Al and Ni/Al, deposited by electron-beam evaporation method) as the catalysts. With a low substrate temperature of 550 °C and above, SWNTs were successfully synthesized on both catalysts, as revealed from the characteristic peaks of SWNTs in the micro-Raman spectra. By the reduction of plasma power and the shortening of the process times, the lowest synthesis temperature of SWNTs achieved in our system was approached to 500 °C on Ni/Al catalysts; on the other hands, the lowest temperature for Fe/Al catalysts was 550 °C. Our results suggest that as compared with Fe/Al, Ni/Al is more favorable for plasma-enhanced CVD (PECVD) synthesis of SWNTs at low temperatures. This work can be used for further improvements and better understanding on the production processes of SWNTs by PECVD methods.

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