Negative Temperature Coefficient of Single-Walled Carbon Nanotube-Gold Nanoparticle Hybrid Structures

2008 ◽  
Vol 8 (5) ◽  
pp. 2522-2525 ◽  
Author(s):  
N. Songmee ◽  
S. Daothong ◽  
P. Singjai
Keyword(s):  
Gold Nanoparticle ◽  
Chemical Vapor ◽  
Negative Temperature ◽  
Ethanol Vapor ◽  
Hybrid Structures ◽  
Single Walled Carbon Nanotube ◽  
Co Catalyst ◽  
Single Walled Carbon ◽  
Quartz Substrates ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes (SWNTs) were grown on gold nanoparticle (GNP) coated quartz substrates by alcohol catalytic chemical vapor deposition. The GNP coated substrates were coated with Co catalyst by a dip-coat method. The growth was then carried out at 800 °C under a pressure of 10 Torr in an atmosphere of ethanol vapor for 30 min. Characterizations have shown larger SWNT diameters with higher negative temperature coefficients for GNP coated substrates as compared to those of quartz substrates without GNPs. It is attributed that SWNT-GNP hybrid structures have a higher fraction of semiconductor-type pathways.

Efficient Synthesis of Individual Single-Walled Carbon Nanotube by Water-Based Catalyst with Poly(vinylpyrrolidone)

2008 ◽  
Vol 8 (1) ◽  
pp. 329-334 ◽  
Author(s):  
Seung Yol Jeong ◽  
Sang Hyun Jeon ◽  
Gang Hee Han ◽  
Kay Hyeok An ◽  
Dong Jae Bae ◽  
...  
Keyword(s):  
Active Sites ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Average Diameter ◽  
Water Soluble ◽  
Excitation Energies ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
The Individual ◽  
Walled Carbon Nanotubes

Individual single-walled carbon nanotubes (SWCNTs) were synthesized on the patterned water-soluble catalyst by thermal chemical vapor deposition. The individual SWCNTs were obtained by introducing polyvinylpyrrolidone (PVP) as a dispersant. The number of SWCNTs between two electrodes were approximately 1 ∼2 with an average diameter of about 1.7 nm and a yield of forming electrodes of nearly 70%. The PVP played an important role in dispersing catalysts and suppressing the active sites to limit the number of SWCNTs during synthesis, which is a critical condition for fabrication of field effect transistors (FETs). The measured I–V characteristics of the over layer-deposited electrodes revealed a clear gating effect in large portion, in good agreement with Raman observations in several excitation energies. The patterning procedure, catalyst preparation, and growth condition for fabrication of the SWCNT-FET were further discussed.

Chemical Vapor Depositions of Single Walled Carbon Nanotube thin films and their applications for sensors in aqueous solutions

2004 ◽  
Vol 828 ◽  
Author(s):  
Qiang Fu ◽  
Lei An ◽  
Chenguang Lu ◽  
Jie Liu
Keyword(s):  
Thin Films ◽  
Aqueous Solutions ◽  
Chemical Sensors ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Surface Charges ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

AbstractHigh-density and high-quality single walled carbon nanotubes are directly grown on surface by Chemical Vapor Depositions. We found that those SWNT thin films could be used to fabricate thin film field-effect transistors. Those transistors are very sensitive to surface charges changes in aqueous solutions and could be used tobuild chemical sensors.

Growth Mechanism of Single-Walled Carbon Nanotubes from Pt Catalysts by Alcohol Catalytic CVD

2015 ◽  
Vol 1752 ◽  
pp. 27-30
Author(s):  
Takahiro Maruyama ◽  
Hiroki Kondo ◽  
Akinari Kozawa ◽  
Takahiro Saida ◽  
Shigeya Naritsuka ◽  
...  
Keyword(s):  
Growth Mechanism ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Pt Catalyst ◽  
Pt Catalysts ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Gas Source ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes

ABSTRACTSingle-walled carbon nanotube (SWCNT) growth from Pt catalysts by an alcohol gas source method, a type of cold-wall chemical vapor deposition (CVD), was investigated. Raman results showed that the diameters of SWCNTs grown from Pt were below 1.2 nm, while transmission electron microscopy (TEM) showed that the diameters of most Pt catalyst particles were above 1.2 nm. This suggests that SWCNT diameters were smaller than Pt catalysts particles. X-ray photoelectron spectroscopy measurements showed that reduction of Pt particles occurred during the SWCNT growth. Based on these experimental data, growth mechanism of SWCNTs was discussed.

scholarly journals Growth of Single-Walled Carbon Nanotubes by Plasma CVD

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Toshiaki Kato ◽  
Rikizo Hatakeyama
Keyword(s):  
Chemical Vapor ◽  
Plasma Cvd ◽  
Low Temperature Synthesis ◽  
Single Walled Carbon Nanotube ◽  
Plasma Chemical Vapor Deposition ◽  
Structure Control ◽  
Single Walled Carbon ◽  
The Mean ◽  
Walled Carbon Nanotubes ◽  
Kinetics Of

Recent research in plasma chemical vapor deposition (CVD) for single-walled carbon nanotube (SWNT) growth has achieved low-temperature synthesis, individually freestanding formation, and structure control of diameter, chirality, and length. Detailed growth kinetics of SWNTs are revealed using a combination of techniques for plasma control and nanomaterial analysis. Plasma CVD also allows tube metallicity to be controlled by tuning the mean diameter of SWNTs. This plasma CVD progress contributes to the next stage of nanotube fabrication, which is required for practical use of SWNTs in a variety of applications.

Vertically Aligned Single-Walled Carbon Nanotube Growth from Ir Catalysts by Alcohol Gas Source Method

MRS Advances ◽  
2019 ◽  
Vol 4 (3-4) ◽  
pp. 225-230
Author(s):  
Takuya Okada ◽  
Takahiro Saida ◽  
Shigeya Naritsuka ◽  
Takahiro Maruyama
Keyword(s):  
Chemical Vapor ◽  
Growth Time ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Si Substrates ◽  
Gas Source ◽  
Vertically Aligned ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth ◽  
Walled Carbon Nanotubes

Abstract:We demonstrated that single-walled carbon nanotubes (SWCNTs) grew from Ir catalysts by an alcohol catalytic chemical vapor deposition (ACCVD) method using a gas source-type CVD system. At an ethanol pressure of 1×10−1 Pa at 800°C, vertically aligned SWCNTs (VA-SWCNTs) were grown on SiO2/Si substrates. As the growth time became longer, the VA-SWCNT became thicker, and it reached almost 5 μm for a growth time of 180 min. The Raman spectroscopy results showed that the diameters of the grown SWCNTs were mainly distributed below 1.1 nm, indicating that the SWCNTs grown from Ir catalysts had small diameters compared with those from other metal catalysts.

Synthesis of Single-Walled Carbon Nanotube Networks on Silicon Nanowires

2007 ◽  
Vol 561-565 ◽  
pp. 1205-1208
Author(s):  
Hideto Yoshida ◽  
Tetsuya Uchiyama ◽  
Jun Kikkawa ◽  
Hideo Kohno ◽  
Seiji Takeda
Keyword(s):  
Silicon Nanowires ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Catalyst Nanoparticles ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Co Catalysts ◽  
Walled Carbon Nanotubes ◽  
Carbon Nanotube Networks

Single-walled carbon nanotubes (SWNTs) have been synthesized on silicon nanowires (SiNWs) by ethanol chemical vapor deposition (CVD) using Co catalysts nanoparticles. The surface SiOx layers assist the formation of catalyst nanoparticles on SiNWs by inhibiting the diffusion of Co to Si. Co-Si compounds have formed in SiNWs readily when the surface SiOx layers are very thin. Therefore, the yield of SWNTs is strongly influenced by the thickness of the surface SiOx layers of SiNWs.

scholarly journals ATOMIC HYDROGEN-DRIVEN SIZE CONTROL OF CATALYTIC NANOPARTICLES FOR SINGLE-WALLED CARBON NANOTUBE GROWTH

NANO ◽  
2008 ◽  
Vol 03 (03) ◽  
pp. 145-153 ◽  
Author(s):  
HEE JIN JEONG ◽  
LAURENT EUDE ◽  
MANOHARAN GOWTHAM ◽  
BERND MARQUARDT ◽  
SUNG HUN LIM ◽  
...  
Keyword(s):  
Low Temperature ◽  
Atomic Hydrogen ◽  
Size Control ◽  
Chemical Vapor ◽  
Catalyst Layer ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Carbon Nanotube Growth ◽  
Nanotube Growth ◽  
Walled Carbon Nanotubes

The effects of an atomic hydrogen ( H at ) pretreatment of the catalyst layer on the low temperature growth of single-walled carbon nanotubes (SWCNTs) have been investigated using a modified catalytic chemical vapor deposition system. Well-defined and isolated individual Fe nanoparticles as a catalyst are successfully formed on the defects with high trapping energy which are created on the Al 2 O 3 surface by H at pretreatment, yielding highly dense SWCNTs. The pretreatment mechanism of H at , compared to H 2 , is also discussed. It was also found that the quality of SWCNTs can be enhanced when H at is flowed with CH 4 during nanotubes growth at low temperature. In this case, the undesired carbon products and defects on catalyst seeds and nanotube walls can be selectively removed by H at . Therefore it is essential to use H at in the pretreatment stage for increasing catalytic activity and to keep the size of nanoparticles in the nm range. H at can also be employed in growth stage for enhancing SWCNTs quality and density at low temperature.

scholarly journals Supramolecular structures of terbium(iii) porphyrin double-decker complexes on a single-walled carbon nanotube surface

RSC Advances ◽  
2019 ◽  
Vol 9 (48) ◽  
pp. 28135-28145
Author(s):  
Ahmed I. A. Abd El-Mageed ◽  
Takuji Ogawa
Keyword(s):  
Carbon Nanotubes ◽  
Scanning Probe Microscopy ◽  
Single Walled Carbon Nanotubes ◽  
Supramolecular Structures ◽  
Scanning Probe ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Double Decker ◽  
Walled Carbon Nanotubes ◽  
First Time

For the first time, using scanning probe microscopy, the supramolecular structures of terbium porphyrin double-decker complexes were observed on single-walled carbon nanotubes surfaces, where the molecules formed a well-ordered self-assembled array.

scholarly journals Free Vibration Analysis of Single Walled Carbon Nanotube with Exponentially Varying Stiffness

2018 ◽  
Vol 5 (1) ◽  
pp. 201-212 ◽  
Author(s):  
Subrat Kumar Jena ◽  
S. Chakraverty
Keyword(s):  
Free Vibration ◽  
Differential Quadrature Method ◽  
Free Vibration Analysis ◽  
Beam Theory ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Scaling Parameters ◽  
Governing Differential Equation ◽  
Theory Application ◽  
Walled Carbon Nanotubes

Abstract In this paper, Differential Quadrature Method (DQM) is applied to investigate free vibration of Single Walled Carbon Nanotubes (SWCNTs) with exponentially varying stiffness based on non-local Euler-Bernoulli beam theory. Application of DQ method in the governing differential equation converts the problem to a generalized eigenvalue problem and its solution gives frequency parameters. Convergence of the results show that DQM solutions converge fast. In this article, a detailed investigation has been reported and MATLAB code has been developed to analyze the numerical results for different scaling parameters as well as for four types of boundary conditions. Present results are compared with other available results and are found to be in good agreement.

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