Effects of Al2O3 Type on Activity of Al2O3-Supported Rh Catalysts in Single-Walled Carbon Nanotubes Growth by CVD

MRS Advances ◽  
2017 ◽  
Vol 2 (02) ◽  
pp. 89-95
Author(s):  
Hoshimitsu Kiribayashi ◽  
Takayuki Fujii ◽  
Takahiro Saida ◽  
Shigeya Naritsuka ◽  
Takahiro Maruyama
Keyword(s):  
Ultra Violet ◽  
Single Walled Carbon Nanotubes ◽  
Buffer Layers ◽  
Particle Sizes ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Surface Migration ◽  
Rh Catalyst ◽  
Walled Carbon Nanotubes

ABSTRACT We carried out single-walled carbon nanotube (SWCNT) growth using a Rh catalyst on Al2O3 buffer layers that were prepared by three different methods based on electron beam (EB) evaporation: native oxidation of Al layer deposited by EB ([EB(Al)+NO]-Al2O3 layer); thermal oxidation of Al layer deposited by EB ([EB(Al)+TO]-Al2O3 layer); EB deposition of Al2O3 layer ([EB(Al2O3)]-Al2O3 layer). SWCNT yield was the largest for the [EB(Al2O3)]-Al2O3 layer, while SWCNTs were not grown on the [EB(Al)+NO]- Al2O3 layer. Transmission electron spectroscopy showed that most of Rh particle sizes were distributed between 1.0 and 2.6 nm on the [EB(Al)+NO]- Al2O3 and [EB(Al2O3)]- Al2O3 layers, while they were distributed between 1.8 and 4.2 nm on the [EB(Al)+TO]- Al2O3 layer. This result indicates that surface migration of Rh catalysts was suppressed on the [EB(Al2O3)]- Al2O3 layer, resulting in the largest SWCNT yield. On the other hand, enlargement of Rh catalyst particles occurred on the [EB(Al)+TO]- Al2O3 layer, leading to the reduction of SWCNT yield. Taking into account our previous study, inward diffusion of Rh catalysts into the Al2O3 buffer layer inhibited SWCNT growth on the [EB(Al)+NO]- Al2O3 layer, although enlargement of Rh particle size was suppressed. We also carried out ultra-violet photoemission measurements for Rh catalysts on the [EB(Al)+TO]- Al2O3 and [EB(Al2O3)]- Al2O3 layers and investigated the electronic states of Rh catalysts on them.

Synthesis of Fe3O4 Nanoparticles to Synthesize Bundles of Single-Walled Carbon Nanotubes

2015 ◽  
Vol 1109 ◽  
pp. 108-112
Author(s):  
Wei Wen Liu ◽  
Azizan Aziz ◽  
Siang Piao Chai ◽  
Abdul Rahman Mohamed ◽  
U. Hashim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Single Walled Carbon Nanotubes ◽  
Average Diameter ◽  
Narrow Size Distribution ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Active Metal ◽  
Tremendous Amount ◽  
Walled Carbon Nanotubes

Magnetite (Fe3O4) nanoparticles were synthesized in aqueous solutions without any surfactants. The Fe3O4 nanoparticles are nearly spherical and have an average diameter of 10.33nm and a narrow size distribution. Bundles of single-walled carbon nanotube (SWCNT) were synthesized using these Fe3O4 nanoparticles supported by MgO. Transmission electron microscopy (TEM) images show that tremendous amount of bundles SWCNT with uniform diameters were produced. The average diameter of bundles SWCNT is 1.22nm. Raman spectrum shows that well graphitized SWCNTs were formed based on the low ratio of ID/IG. Fe3O4 nanoparticles could be an effective active metal to synthesize large quantity bundles of SWCNT.

scholarly journals Organic molecules encapsulated in single-walled carbon nanotubes

2021 ◽  
Author(s):  
Ana Cadena ◽  
Bea Botka ◽  
Katalin Kamarás
Keyword(s):  
Carbon Nanotubes ◽  
Organic Molecules ◽  
Single Walled Carbon Nanotubes ◽  
Structural Transformations ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Yield Information ◽  
Broad Variety ◽  
Walled Carbon Nanotubes

Abstract Hybrid materials based on carbon nanotubes continue to attract considerable interest due to the broad variety of both the cages outside and the encapsulated species inside. This review focuses on organic molecules as guests in single-walled carbon nanotube hosts. The majority of results presented here have been attained in recent years by various methods of optical spectroscopy, complemented by transmission electron microscopy. These spectroscopic methods yield information on electronic structure, as well as dynamic processes as structural transformations and chemical reactions.

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.

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.

Image Restoration of One-Dimensional HgTe Crystals Formed within Single Walled Carbon Nanotubes

2006 ◽  
Vol 514-516 ◽  
pp. 1131-1134
Author(s):  
Jeremy Sloan ◽  
Robin Carter ◽  
Angus I. Kirkland ◽  
Rüdiger R. Meyer ◽  
Alexis Vlandas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Three Dimensional ◽  
Single Walled Carbon Nanotubes ◽  
One Dimensional ◽  
Single Walled Carbon ◽  
Semiconductor Crystals ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes ◽  
Separate Crystal

Restored high resolution transmission electron microscopy (HRTEM) images have been recorded from 1D semiconductor crystals formed within narrow diameter (ca. 1.4 nm) single walled carbon nanotubes (SWNTs). Two unique projections were obtained from separate crystal fragments encapsulated within separate nanotubes that has facilitated the reconstruction of the three dimensional arrangement of atoms within the two encapsulated fragments.

Dependence of the Elastic Properties of a Single-Walled Carbon Nanotube on its Chirality

2018 ◽  
Vol 284 ◽  
pp. 20-24
Author(s):  
E.S. Sergeeva
Keyword(s):  
Carbon Nanotube ◽  
Elastic Properties ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Extreme Loads ◽  
Structure Sensitive ◽  
Different Types ◽  
Walled Carbon Nanotubes ◽  
Elastic Characteristics

Currently, composite materials composed of a matrix and reinforcing components are widely used as a structural material for various engineering devices designed to operate under extreme loads of different types. By modifying a composite with structure-sensitive inclusions, such as a single-wall carbon nanotube, the mechanical properties, especially elastic characteristics, of the resulting material can be significantly improved. The results of investigation of a single-walled carbon nanotubes chirality influence on its elastic properties are presented. Various configurations of nanotubes, such as zigzag and armchair are considered. The dependences of the nanotube bulk modulus and shear modulus of its diameter are shown.

Highly efficient thermophones based on freestanding single-walled carbon nanotube films

2019 ◽  
Vol 4 (5) ◽  
pp. 1158-1163 ◽  
Author(s):  
Stepan A. Romanov ◽  
Ali E. Aliev ◽  
Boris V. Fine ◽  
Anton S. Anisimov ◽  
Albert G. Nasibulin
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
State Of The Art ◽  
Single Walled Carbon Nanotubes ◽  
The State ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Highly Efficient ◽  
Art Performance ◽  
Walled Carbon Nanotubes

We present the state-of-the-art performance of air-coupled thermophones made of thin, freestanding films of randomly oriented single-walled carbon nanotubes (SWCNTs).

scholarly journals The Long-Term Fate and Toxicity of PEG-Modified Single-Walled Carbon Nanotube Isoliquiritigenin Delivery Vehicles in Rats

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Bo Han ◽  
Mingming Zhang ◽  
Ting Tang ◽  
Qiusheng Zheng ◽  
Keyu Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Molecular Weight ◽  
Single Walled Carbon Nanotubes ◽  
Blood Clearance ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Tissue Sections ◽  
Covalently Linked ◽  
Walled Carbon Nanotubes

Oxidized single-walled carbon nanotubes (o-SWNTs) was modified by covalently and noncovalently linking PEG to the o-SWNTs. The influence of oxidation time, PEG molecular weight, and type of PEG linkage on the blood clearance time of PEG-modified single-walled carbon nanotubes (SWNTs) was investigated. The toxicity profile of SWNTs covalently linked to PEG (c-PEG-o-SWNTs) in rats has also been determined. The pharmacokinetics of c-PEG-o-SWNTs in rats and their distribution in vital organs were monitored by Raman spectroscopy, and the blood clearance of homogenate isoliquiritigenin (ISL) was determined by HPLC. Photos of tissue and tissue sections were taken to evaluate the toxicity of c-PEG-o-SWNTs. We found that SWNTs which were covalently modified with PEG and have a molecular weight of 3500 had the longest blood clearance half-lives. However, SWNTs were toxic to the kidneys and the hearts. The high renal clearance of long-term fate SWNTs may occur because of impaired kidney filtration function. Therefore, we assume that while researchers study the long-term fate of SWNTs, the toxicity of SWNTs also needs to be taken into account.

Preparation of Single-Walled Carbon Nanotubes from Starch by Arc Discharge

2012 ◽  
Vol 454 ◽  
pp. 63-66
Author(s):  
Xia Yuan ◽  
Yu Liang An ◽  
Chen Zhang ◽  
Hong Chao Sui
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Arc Discharge ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon ◽  
Transmission Electron ◽  
Walled Carbon Nanotubes ◽  
Discharge Method ◽  
Scanning Electron

Single-walled carbon nanotubes (SWNTs) have been successfully prepared from starch by arc discharge technique. The SWNTs products were characterized by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The growth mechanism of the SWNTs was discussed in terms of the starch. The results demonstrate that starch is one of the suitable precursor for making SWNTs by arc discharge method.

Photochemical generation of bis-hexahapto chromium interconnects between the graphene surfaces of single-walled carbon nanotubes

2015 ◽  
Vol 2 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Aron Pekker ◽  
Mingguang Chen ◽  
Elena Bekyarova ◽  
Robert C. Haddon
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Single Walled Carbon Nanotubes ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Photochemical Generation ◽  
Carbon Nanotube Junctions ◽  
Walled Carbon Nanotubes

The linkage of single-walled carbon nanotube junctions by the photochemistry of organometallic chromium reagents produces dramatic increases in network conductivity.

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