scholarly journals Carbon Nanotube-Quicklime Nanocomposites Prepared Using a Nickel Catalyst Supported on Calcium Oxide Derived from Carbonate Stones

Nanomaterials ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 1239 ◽  
Author(s):  
Ruzanna Ibrahim ◽  
Mohd Zobir Hussein ◽  
Nor Azah Yusof ◽  
Fatimah Abu Bakar

Carbon nanotube-quicklime nanocomposites (CQNs) have been synthesized via the chemical vapor deposition (CVD) of n-hexane using a nickel metal catalyst supported on calcined carbonate stones at temperatures of 600–900 °C. The use of a Ni/CaO(10 wt%) catalyst required temperatures of at least 700 °C to obtain XRD peaks attributable to carbon nanotubes (CNTs). The CQNs prepared using a Ni/CaO catalyst of various Ni contents showed varying diameters and the remaining catalyst metal particles could still be observed in the samples. Thermogravimetric analysis of the CQNs showed that there were two major weight losses due to the amorphous carbon decomposition (300–400 °C) and oxidation of CNTs (400–600 °C). Raman spectroscopy results showed that the CQNs with the highest graphitization were synthesized using Ni/CaO (10 wt%) at 800 °C with an IG/ID ratio of 1.30. The cyclic voltammetry (CV) of screen-printed carbon electrodes (SPCEs) modified with the CQNs showed that the performance of nanocomposite-modified SPCEs were better than bare SPCEs. When compared to carboxylated multi-walled carbon nanotubes or MWNT–COOH-modified SPCEs, the CQNs synthesized using Ni/CaO (10 wt%) at 800 °C gave higher CV peak currents and comparable electron transfer, making it a good alternative for screen-printed electrode modification.

2010 ◽  
Vol 160-162 ◽  
pp. 737-742 ◽  
Author(s):  
J.W. Zhang ◽  
Zhen Luo ◽  
Y.L. Li ◽  
J.D. Zhu ◽  
J. Hao

A simple and reliable welding method was developed to weld carbon nanotubes with the power supply here. The carbon nanotubes were synthesized chemical vapor deposition method and Multi-walled carbon nanotubes was uesd here. Firstly, apply less than 5 V voltages between carbon nanotubes when they were in close proximity under direct view of optical microscope. Then, let carbon nanotube contact with each other and increase the external voltage to 7–8V until carbon nanotube was attached to the end of the other, the two carbon nanotube join into a carbon nanotube. Furthermore, some experiments were implemented to analyze the reliability, the images of the weld joint and the weld strength all indicted this method were reliable.


2021 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
Putri Ayu Anggoro ◽  
Teguh Endah Saraswati

<p><em>Carbon Nanotube</em> (CNT) memiliki aplikasi potensial yang luas karena sifat kimia dan fisiknya yang sangat baik. CNT disintesis menggunakan prekursor cair dari bahan alam yang. Prekursor cair dari bahan alam dimungkinkan dapat mengganti prekursor berbasis minyak bumi. Minyak kamper, jarak, kayu putih, dan kelapa sawit digunakan sebagai reservoir karbon untuk menghasilkan CNT berdinding banyak (MWCNT). Berbagai metode telah digunakan untuk menghasilkan CNT, termasuk ablasi laser, <em>arc discharge</em> dan proses deposisi uap kimia (CVD). Ulasan ini menjelaskan pembuatan CNT menggunakan metode CVD dikarenakan metode ini adalah metode yang umum digunakan dan sederhana. MWCNT yang dihasilkan dimodifikasi untuk membentuk komposit dengan resin epoksi.</p><p><strong><em>Synthesis of Carbon Nanotubes (CNT) Using Natural Material Precursors and Modified CNTs as CNT/Epoxy Resin Composite: Review. </em></strong>Carbon Nanotubes (CNT) have wide potential applications due to their excellent chemical and physical properties. CNTs were synthesized using liquid precursors from natural materials possibly replacing petroleum-based precursors. Camphor, jatropha, eucalyptus oil, and palm oil are used as carbon reservoirs to produce multi-walled carbon nanotubes (MWCNT). A variety of methods have been used to produce CNTs, including laser ablation, arc discharge, and chemical vapor deposition (CVD) processes. This mini-review explained the manufacture of CNTs using the CVD method as a commonly used and simple method. The synthesized CNT is then modified to be applied to form a composite with epoxy resin</p>


Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 361 ◽  
Author(s):  
Paul Kim ◽  
Cheol Lee

Diameters and crystallinity of multi-walled carbon nanotubes (MWCNTs) dependent on reduction temperature of the Fe–Co/MgO catalyst were investigated. MWCNTs were synthesized by catalytic chemical vapor depositing and the Fe–Co/MgO catalyst was fabricated by using a sol-gel method. According to Raman analysis, transmission electron microscopy and thermogravimetric analysis, the diameter distribution of MWCNTs was broadened with increasing reduction temperature of the Fe–Co/MgO catalyst and crystallinity was improved. The above results are attributed to an increased size and enhanced crystallinity of metal catalyst particles by increasing reduction temperature.


2004 ◽  
Vol 837 ◽  
Author(s):  
Yong-Won Lee ◽  
Rohit Deshpande ◽  
Anne C. Dillon ◽  
Michael J. Hebe ◽  
Hongjie Dai ◽  
...  

ABSTRACTMultiwalled carbon nanotubes (MWNTs) were continuously synthesized by hot wire chemical vapor deposition (HWCVD) using a methane source catalyzed by metal-organic ferrocene. The microstructure of the MWNTs and the catalyst particles were subsequently characterized with transmission electron microscopy which identified three different phases, i.e., bcc α-Fe, fcc γ-Fe and orthorhombic Fe3C. The hydrogen storage capacity of MWNTs was determined with temperature-programmed desorption (TPD) technique. Hydrogen adsorption at near ambient conditions was observed only in as-synthesized MWNTs containing iron particles and was dramatically increased after hydrogen reducing treatment. Possible adsorption mechanism was also discussed.


2003 ◽  
Vol 772 ◽  
Author(s):  
Masakazu Muroyama ◽  
Kazuto Kimura ◽  
Takao Yagi ◽  
Ichiro Saito

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.


2007 ◽  
Vol 124-126 ◽  
pp. 1309-1312
Author(s):  
Nguyen Duc Hoa ◽  
Nguyen Van Quy ◽  
Gyu Seok Choi ◽  
You Suk Cho ◽  
Se Young Jeong ◽  
...  

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.


Carbon ◽  
2011 ◽  
Vol 49 (13) ◽  
pp. 4138-4148 ◽  
Author(s):  
Zhuo Li ◽  
Wei Lin ◽  
Kyoung-Sik Moon ◽  
Stewart J. Wilkins ◽  
Yagang Yao ◽  
...  

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