scholarly journals Diameter Tuning of Single-Walled Carbon Nanotubes by Diffusion Plasma CVD

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Toshiaki Kato ◽  
Shunsuke Kuroda ◽  
Rikizo Hatakeyama
Keyword(s):  
Carbon Nanotubes ◽  
High Performance ◽  
Large Diameter ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Diameter Distribution ◽  
Plasma Cvd ◽  
Single Walled Carbon ◽  
Process Gas ◽  
Walled Carbon Nanotubes

We have realized a diameter tuning of single-walled carbon nanotubes (SWNTs) by adjusting process gas pressures with plasma chemical vapor deposition (CVD). Detailed photoluminescence measurements reveal that the diameter distribution of SWNTs clearly shifts to a large-diameter region with an increase in the pressure during plasma CVD, which is also confirmed by Raman scattering spectroscopy. Based on the systematical investigation, it is found that the main diameter of SWNTs is determined by the pressure during the heating in an atmosphere of hydrogen and the diameter distribution is narrowed by adjusting the pressure during the plasma generation. Our results could contribute to an application of SWNTs to high-performance thin-film transistors, which requires the diameter-controlled semiconductor-rich SWNTs.

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.

Synthesis of single-walled carbon nanotubes on graphene layers

2015 ◽  
Vol 51 (43) ◽  
pp. 8974-8977 ◽  
Author(s):  
Ranajit Ghosh ◽  
Takahiro Maruyama ◽  
Hiroki Kondo ◽  
Koji Kimoto ◽  
Takuro Nagai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Diameter Distribution ◽  
Graphene Layers ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes ◽  
Narrow Diameter Distribution

Single-walled carbon nanotubes with a narrow diameter distribution are grown on graphene layers via chemical vapor deposition.

Diameter-Selective Synthesis of Single-Walled Carbon Nanotubes on Supported Cobalt Catalysts

NANO ◽  
2019 ◽  
Vol 14 (08) ◽  
pp. 1950106
Author(s):  
Hong Wang ◽  
Lian Yang ◽  
Pingting Chen ◽  
Xiaodong Tang ◽  
Jin Yang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
High Surface ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Selective Growth ◽  
Cobalt Catalysts ◽  
Diameter Distribution ◽  
Single Walled Carbon ◽  
Co Catalysts ◽  
Walled Carbon Nanotubes

Supported Co catalysts were prepared by impregnating the support (MgO, SiO2 and Al2O[Formula: see text] with Co(acac)2 solution, and diameter-selective growth of single-walled carbon nanotubes (SWCNTs) by ethanol chemical vapor deposition has been assessed on these Co catalysts. In contrast to Co/SiO2 and Co/Al2O3 catalysts with relatively high surface areas, Co/MgO catalyst with a low surface area demonstrates the best performances in the diameter-selective growth of SWCNTs under an optimal growth condition. Multiple characterizations on catalysts and SWCNTs revealed that Co(acac)2 was absorbed on MgO by ligand exchange and anhydrous solvent CH2Cl2 strengthened the anchoring of Co(acac)2 on the MgO surface, which resulted in well-dispersed Co species upon calcination in air. Under a modest reduction temperature, the reduction of Co oxides provided Co clusters, which were anchored by the unreacted Co ions in the interior of MgO support, leading to the synthesis of SWCNTs with a narrow diameter distribution.

Effect of DC Bias on Microwave Plasma Enhanced Chemical Vapor Deposition Synthesis of Single-Walled Carbon Nanotubes

2005 ◽  
Author(s):  
Matthew R. Maschmann ◽  
Placidus B. Amama ◽  
Timothy S. Fisher
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Single Walled Carbon Nanotubes ◽  
Diameter Distribution ◽  
Single Walled Carbon ◽  
Dc Bias ◽  
Walled Carbon Nanotubes

The physical properties of carbon nanotubes (CNTs) make them outstanding candidates for introduction into technologies ranging from high resolution flat panel displays to nanoscale transistors. Integration of carbon nanotubes into devices, however, requires precise control over the manufacturing processes used during their synthesis. To meet the specific requirements of a given application, alignment, diameter, length and chirality of carbon nanotubes must be strictly addressed. This work demonstrates the controlled synthesis of single-walled carbon nanotubes (SWCNTs) with low amount of undesired carbonaceous species using plasma enhanced chemical vapor deposition (PECVD). This report elucidates the role of DC bias applied to the growth substrate during synthesis, including the field-enhanced alignment of SWCNTs, selectivity in the diameter distribution and selectivity of semiconducting versus metallic nanotubes. Carbon nanotubes are characterized using Raman spectroscopy and electron microscopy.

scholarly journals Synthesis of silver nanoparticles embedded with single-walled carbon nanotubes for printable elastic electrodes and sensors with high stability

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jae-Won Lee ◽  
Joon Young Cho ◽  
Mi Jeong Kim ◽  
Jung Hoon Kim ◽  
Jong Hwan Park ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Silver Nanoparticles ◽  
High Performance ◽  
Composite Films ◽  
Single Walled Carbon Nanotubes ◽  
Gauge Factor ◽  
Time Interval ◽  
Single Walled Carbon ◽  
Irradiation Energy ◽  
Walled Carbon Nanotubes

AbstractSoft electronic devices that are bendable and stretchable require stretchable electric or electronic components. Nanostructured conducting materials or soft conducting polymers are one of the most promising fillers to achieve high performance and durability. Here, we report silver nanoparticles (AgNPs) embedded with single-walled carbon nanotubes (SWCNTs) synthesized in aqueous solutions at room temperature, using NaBH4 as a reducing agent in the presence of highly oxidized SWCNTs as efficient nucleation agents. Elastic composite films composed of the AgNPs-embedded SWCNTs, Ag flake, and polydimethylsiloxane are irradiated with radiation from a Xenon flash lamp within a time interval of one second for efficient sintering of conductive fillers. Under high irradiation energy, the stretchable electrodes are created with a maximum conductivity of 4,907 S cm−1 and a highly stretchable stability of over 10,000 cycles under a 20% strain. Moreover, under a low irradiation energy, strain sensors with a gauge factor of 76 under a 20% strain and 5.4 under a 5% strain are fabricated. For practical demonstration, the fabricated stretchable electrode and strain sensor are attached to a human finger for detecting the motions of the finger.

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