Effects of Catalyst Promoters on the Growth of Single-Layer Carbon Nanotubes

1994 ◽  
Vol 359 ◽  
Author(s):  
Ching-Hwa Kiang ◽  
William A. Goddard ◽  
Robert Beyers ◽  
Jesse R. Salem ◽  
Donald S. Bethune
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Production Efficiency ◽  
Single Layer ◽  
Catalytic Process ◽  
Present Understanding

ABSTRACTThe discovery of a catalytic route to the growth of single-layer carbon nanotubes suggests that it may be possible to produce these materials with better selectivity and in higher yield. Increasing the production efficiency is essential for characterization and application of these materials. We have discovered several catalyst promoters, in particular S, Bi, and Pb, that greatly enhance the single-layer carbon nanotube yield, and extend the distribution of nanotube diameters to much larger sizes (> 3 nm). Co crystallites encapsulated in graphitic polyhedra also form abundantly when S, Bi, or W is present. Understanding these catalytic process is of substantial scientific and technological importance.

scholarly journals Surface Functionalization of Boron-Carbon BС5 Nanotubes by a Nitro Group As a Sensor Device Element: Theoretical Research

2021 ◽  
pp. 27-34
Author(s):  
Irina Zaporotskova ◽  
◽  
Evgeniy Dryuchkov ◽  
Maria Chesheva ◽  
Daria Zvonareva ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Alkali Metal ◽  
Nitro Group ◽  
Single Layer ◽  
Basis Set ◽  
Molecular Cluster ◽  
Sensor Device ◽  
Metal Atoms ◽  
Boron Carbon

The problem of modification of boron-carbon nanotubes (BCNT) by functional groups is relevant in connection with the intensive development of the nano industry, in particular, nano- and microelectronics. For example, a modified nanotube can be used as an element of a sensor device for detecting microenvironments of various substances, in particular metals included in salts and alkalis. The paper discusses the possibility of creating a high-performance sensor using single-layer boron-carbon nanotubes as a sensitive element, the surface of which is modified with a functional nitro group -NO2. Quantum-chemical studies of the process of attaching a nitro group to the outer surface of a single-layer boron-carbon nanotube (BCNT) of type (6, 6) were carried out, which proved the possibility of modifying the BCNT and the formation of a bond between the group -NO2 and the carbon atom of the surface of the nanotube. The results of computer simulation of interaction of surface-modified boron-carbon nanotube with alkali metal atoms (lithium, sodium, potassium) are presented. The sensory interaction of the modified boron-carbon nanosystem with the selected metal atoms was investigated, which proved the possibility of identifying these atoms using a nanotubular system that can act as an element of the sensor device. When reacting with alkali metal atoms in the “BСNT+NO 2” complex, the number of basic carriers increases, due to the transfer of electron density from metal atoms to modified BСNT. The results presented in this paper were obtained using the molecular cluster model and the calculated DFT method with exchange-correlation functionality B3LYP (valence-split basis set 6-31G).

Fabrication of Carbon Nanotube Triode Using Helicon Plasma Cvd with Electroplated Nico Catalyst

2003 ◽  
Vol 772 ◽  
Author(s):  
Masakazu Muroyama ◽  
Kazuto Kimura ◽  
Takao Yagi ◽  
Ichiro Saito
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Metal Catalyst ◽  
Ni Catalyst ◽  
Plasma Cvd ◽  
Helicon Plasma ◽  
Plasma Enhanced Cvd ◽  
Turn On ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned

AbstractA carbon nanotube triode using Helicon Plasma-enhanced CVD with electroplated NiCo catalyst has been successfully fabricated. Isolated NiCo based metal catalyst was deposited at the bottom of the cathode wells by electroplating methods to control the density of carbon nanotubes and also reduce the activation energy of its growth. Helicon Plasma-enhanced CVD (HPECVD) has been used to deposit nanotubes at 400°C. Vertically aligned carbon nanotubes were then grown selectively on the electroplated Ni catalyst. Field emission measurements were performed with a triode structure. At a cathode to anode gap of 1.1mm, the turn on voltage for the gate was 170V.

scholarly journals Explosive Molecule Sensing at Lattice Defect Sites in Metallic Carbon Nanotubes

2021 ◽  
Author(s):  
Manasi Doshi ◽  
Eric Paul Fahrenthold
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Experimental Research ◽  
Gas Sensing ◽  
Lattice Defect ◽  
Sensing Mechanism ◽  
Defect Sites ◽  
Chemiresistive Sensing ◽  
Hazardous Gas

Explosives and hazardous gas sensing using carbon nanotube (CNT) based sensors has been a focus of considerable experimental research. The simplest sensors have employed a chemiresistive sensing mechanism, and rely...

Cure Behavior Changes and Compression of Carbon Nanotubes in Aerospace Grade Bismaleimide-Carbon Nanotube Sheet Nanocomposites

2021 ◽  
Author(s):  
Mohammad Hamza Kirmani ◽  
Geeta Sachdeva ◽  
Ravindra Pandey ◽  
Gregory M. Odegard ◽  
Richard Liang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Behavior Changes ◽  
Cure Behavior

Carbon Nanotube Gas Sensor Fabricated on Anodic Aluminum Oxide

2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Gas Sensor ◽  
Chemical Vapor ◽  
Fast Response ◽  
Device Fabrication ◽  
Alumina Oxide ◽  
Response And Recovery ◽  
New Type ◽  
P Type

A new type of gas sensor was realized by directly depositing carbon nanotube on nano channels of the anodic alumina oxide (AAO) fabricated on p-type silicon substrate. The carbon nanotubes were synthesized by thermal chemical vapor deposition at a very high temperature of 1200 oC to improve the crystallinity. The device fabrication process was also developed. The contact of carbon nanotubes and p-type Si substrate showed a Schottky behavior, and the Schottky barrier height increased with exposure to gases while the overall conductivity decreased. The sensors showed fast response and recovery to ammonia gas upon the filling (400 mTorr) and evacuation.

scholarly journals Study on the nonlinear vibration of embedded carbon nanotube via the Hamiltonian-based method

2021 ◽  
pp. 146134842110327
Author(s):  
Kang-Jia Wang ◽  
Guo-Dong Wang
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nonlinear Vibration ◽  
Elastic Medium ◽  
Numerical Results ◽  
Frequency Property ◽  
New Novel ◽  
Novel Method

This article mainly studies the vibration of the carbon nanotubes embedded in elastic medium. A new novel method called the Hamiltonian-based method is applied to determine the frequency property of the nonlinear vibration. Finally, the effectiveness and reliability of the proposed method is verified through the numerical results. The obtained results in this work are expected to be helpful for the study of the nonlinear vibration.

scholarly journals A nuclear spin and spatial symmetry-adapted full quantum method for light particles inside carbon nanotubes: clusters of 3He, 4He, and para-H2

2021 ◽  
Author(s):  
María Pilar de Lara-Castells ◽  
Alexander O. Mitrushchenkov
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Nuclear Spin ◽  
Spatial Symmetry ◽  
Quantum Method ◽  
Light Particles ◽  
Full Quantum

A new nuclear spin and spatial symmetry-adapted full quantum method for light fermionic and bosonic particles under cylindrical carbon nanotube confinement.

Preparation of a Functional Enzyme–Carbon Nanotube Complex by the Immobilization of Superoxide Dismutase on Single-Wall Carbon Nanotubes

2018 ◽  
Vol 13 (7-8) ◽  
pp. 349-355 ◽  
Author(s):  
D. K. Shishkova ◽  
Yu. I. Khodyrevskaya ◽  
A. G. Kutikhin ◽  
M. S. Rybakov ◽  
R. A. Mukhamadiyarov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Superoxide Dismutase ◽  
Carbon Nanotube ◽  
Single Wall Carbon Nanotubes ◽  
Single Wall Carbon
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