scholarly journals Raman Characteristics of Multiwall Carbon Nanotubes on Diatomite

2018 ◽  
pp. 319
Author(s):  
M. Nazhipkyzy ◽  
A. Nurgain ◽  
A.A. Zhaparova ◽  
A.R. Seitkazinova ◽  
N.G. Prikhodko ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Treatment Process ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Experimental Conditions ◽  
Intensity Ratios ◽  
Multiwall Carbon ◽  
Propane Butane

In this paper, the diatomite mineral from Mugalzhar field, Aktobe region, has been used as a matrix of catalyst particles to synthesize multiwall carbon nanotubes (MWCNTs) by Catalytic Chemical Vapor Deposition method (CCVD). As a source of carbon was used a propane-butane gas mixture, as a catalyst – Ni particles deposited from Ni(NO3)2 solution during heat treatment process at 400–500 °C. The CCVD method was conducted at a different temperature: 650 °C, 700 °C, 750 °C, 800 °C. Obtained MWCNTs were studied by Raman spectroscopy. The characteristics such as crystallinity, defectiveness, diameter of MWCNTs synthesized at different experimental conditions were evaluated from the positions and intensity ratios of Raman peaks of the samples. The results of investigations of the properties of the obtained carbon nanotubes show the dependence of MWCNTs characteristics on CCVD method temperature. The observation of changes in all the three peaks – D, G and 2D, of obtained materials exhibit, that MWCNTs synthesized at 800 °C possess high crystallinity, low defectiveness and larger diameters as compared with carbon nanotubes grown at 650 °C, 700 °C, 750 °C.

Growth of Carbon Nanotubes on Surface of Carbon Fibers Rod

2006 ◽  
Vol 317-318 ◽  
pp. 259-262 ◽  
Author(s):  
Yun Soo Lim ◽  
Woo Sik Kim ◽  
Sook Young Moon ◽  
Dong Yun Han ◽  
Jin Yong Lee
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fibers ◽  
Vapor Deposition ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Deposition Method ◽  
Experimental Conditions ◽  
Fe Catalysts ◽  
Multiwall Carbon

The growth of carbon nanotubes (CNTs) from surface of carbon fibers rods (CFRs) as used supports is under investigation using the Fe-catalytic chemical vapor deposition method. TEM studies indicate that under the experimental conditions Fe catalysts on CFRs produces mostly bundles of multiwall carbon nanotubes (MWCNTs). SEM results show the best presence of bundles of MWCNTs for Fe catalysts of 6.5 mol % at 800°C.

scholarly journals Magnetic and Electrical Properties of Nitrogen-Doped Multiwall Carbon Nanotubes Fabricated by a Modified Chemical Vapor Deposition Method

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
María Luisa García-Betancourt ◽  
Yadira Itzel Vega-Cantu ◽  
Sofía Magdalena Vega-Díaz ◽  
Aarón Morelos-Gómez ◽  
Mauricio Terrones ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Morphological Changes ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Nitrogen Doped ◽  
Multiwall Carbon

Chemical vapor deposition (CVD) is a preferential method to fabricate carbon nanotubes (CNTs). Several changes have been proposed to obtain improved CNTs. In this work we have fabricated nitrogen-doped multiwall carbon nanotubes (N-MWCNTs) by means of a CVD which has been slightly modified. Such modification consists in changing the content of the by-product trap. Instead of acetone, we have half-filled the trap with an aqueous solution of NaCl (0–26.82 wt.%). Scanning electron microscope (SEM) characterization showed morphological changes depending upon concentration of NaCl included in the trap. Using high resolution transmission electron microscopy several shape changes on the catalyst nanoparticles were also observed. According to Raman spectroscopy results N-MWCNTs fabricated using pure distillate water exhibit better crystallinity. Resistivity measurements performed on different samples by physical properties measurement Evercool system (PPMS) showed metallic to semiconducting temperature dependent transitions when high content of NaCl is used. Results of magnetic properties show a ferromagnetic response to static magnetic fields and the coercive fields were very similar for all the studied cases. However, saturation magnetization is decreased if aqueous solution of NaCl is used in the trap.

Chemical vapor deposition of nickel-group metals on multiwall carbon nanotubes

2007 ◽  
Vol 85 (10) ◽  
pp. 645-650 ◽  
Author(s):  
Maoqi Feng ◽  
Richard J Puddephatt
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Carbon Nanotube ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Multiwall Carbon Nanotubes ◽  
Chemical Vapor ◽  
Pt Films ◽  
Bimetallic Films ◽  
Multiwall Carbon

Chemical vapor deposition (CVD) of Ni, Pd, and Pt films and of Ni/Pd and Pd/Pt bimetallic films on multiwall carbon nanotubes (MWCNTs) can be effected at low temperature if the nanotubes are pretreated by CVD of titanium carbide. In the absence of the pretreatment, the CVD leads to formation of isolated nanoparticles of the nickel-group metals. The metallized MWCNTs are curved or kinked, as a result of the interaction with the metal. Preliminary oxidation of the carbon nanotubes allows easier metallization, and the bending of the metallated nanotubes is not observed in this case.Key words: Chemical vapor deposition, platinum, palladium, nickel, carbon, nanotube.

Optimization of Chemical Vapor Deposition Synthesis Conditions for Multiwall Carbon Nanotube by Statistical Analysis of Experiment

2008 ◽  
Vol 55-57 ◽  
pp. 533-536
Author(s):  
P. Saiprasert ◽  
D. Koolpiruck ◽  
S. Chiangga
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Multiwall Carbon Nanotubes ◽  
Statistical Design ◽  
Chemical Vapor ◽  
Multiwall Carbon Nanotube ◽  
Synthesis Conditions ◽  
Fourier Transform Raman ◽  
Multiwall Carbon

The optimization of chemical vapor deposition synthesis conditions for multiwall carbon nanotubes (MWCNTs) was experimentally investigated. Carbon nanotubes were grown on cobalt substrate thicknesses of 20, 100 and 1000 nm at 700 and 900 0C with 2 replications. The configuration and morphology of the carbon nanotubes were investigated by scanning electron microscope and Fourier transform raman spectrometer, respectively. The tendency of the parameters was evaluated by statistical design of experiment. Observations on samples produced under our optimised production process, showed that a large number of MWCNTs bundles were produced. Diameter of MWCNTs bundles ranges between 30 and 100 nm throughout the samples. From the variance analysis of the Raman spectra we observe that the thickness of cobalt and temperature of synthesis are highly significant in which the coherence length and innermost diameter increase for either the thickness increases or the temperature decreases.

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