scholarly journals Effect of Temperature on Gravity Assisted Synthesis of Carbon Nanotubes by Spray Pyrolysis

2021 ◽  
Vol 33 (5) ◽  
pp. 989-993
Author(s):  
E. Kanagaraj ◽  
P. Mahalingam ◽  
R. Siddharthan ◽  
C. Sathishkumar

Carbon nanotubes were prepared along the gravity direction in a spray pyrolysis setup over the silica supported Fe-Co-Ni catalyst. The silica supported Fe-Co-Ni catalyst coated by jet nebulized spray pyrolysis method over copper strip was inverted to face downward, so that carbon nanotubes can be prepared along the direction of gravity. From the point of view of green chemistry, instead of commonly used hydrocarbons, a plant based natural precursor, pine oil is used as carbon precursor for preparation of carbon nanotubes. The effect of temperature on yield and morphology of carbon nanotubes grown along gravity was studied. The yield of carbon nanotubes was calculated as mass percentage of catalyst and support. The carbon nanotubes were characterized using XRD, SEM, Raman and TGA techniques. The carbon deposit obtained at 650 ºC contains multi-walled carbon nanotubes in larger quantity with very less amorphous carbon. A narrow, lengthy and well graphitized multi-walled carbon nanotubes were formed when the carbon nanotubes grow along the gravity.

2020 ◽  
Vol 26 (S2) ◽  
pp. 2436-2438
Author(s):  
A. Zamudio-Hernández ◽  
J. J. Sánchez-Cuevas ◽  
C. Mercado-Zúñiga ◽  
J. Zárate-Medina ◽  
Gerardo Rosas

2013 ◽  
Vol 652-654 ◽  
pp. 151-154
Author(s):  
Ting Kai Zhao ◽  
Xing Zhao ◽  
Jin Yan ◽  
Li Du ◽  
Tie Hu Li

With the technological progress in the synthesis of multi-walled carbon nanotubes and single-walled carbon nanotubes, more attention was attracted to the synthesis of carbon nanotubes with diameter distribution, ideal length, different chirality and certain orientation. In recent decade, all these factors have been investigated and a number of progresses have been made for the application of carbon nanotubes. The latest researches on the growth of diameter-controlled single-walled carbon nanotubes are reviewed and discussed. The existing problems and challenges of the synthesis processes have been addressed in the future directions.


2006 ◽  
Vol 320 ◽  
pp. 163-166 ◽  
Author(s):  
Koji Yamada ◽  
Kentaro Abe ◽  
Masafumi Mikami ◽  
Morihiro Saito ◽  
Jun Kuwano

Multi-walled carbon nanotubes (MWCNTs) were synthesized from camphor by a chemical vapor deposition (CVD) method in a range of 750-900. The catalyst was fed in three ways: (a) a sputtered Fe-film on a quartz substrate (b) vaporized ferrocene in an Ar flow; (c) both of (a) and (b). In the case (c), highly pure, dense and aligned MWCNT arrays formed on the quartz substrate at 850, whereas nonaligned MWCNTs formed in the cases (a) and (b).


2015 ◽  
Vol 1107 ◽  
pp. 314-319
Author(s):  
Mai Woon Lee ◽  
Muhammad Aniq Shazni Mohammad Haniff ◽  
Au Shih Teh ◽  
Daniel C.S. Bien ◽  
Soo Kien Chen ◽  
...  

In this paper, the effect of nickel (Ni) catalyst on the growth of carbon nanotubes (CNTs) was studied where the CNTs were vertically grown by plasma enhanced chemical vapor deposition (PECVD) method. The growth conditions were fixed at a temperature of 700°C with a pressure of 1000mTorr for 40 minutes with various thicknesses of sputtered Ni catalyst. Experimental results show that high density of CNTs was observed especially towards thicker catalyst layers where larger and taller nanotubes were formed. The growth rate increases by ~0.7 times with increasing catalyst thickness from 4nm to 10nm. The nucleation of the catalyst with various thicknesses was also studied as the absorption of the carbon feedstock is dependent on the initial size of the catalyst island. From the Raman results, we found that only slight variation in the intensity ratio of G-band over D-band as increasing catalyst thicknesses. The minor difference in G/D ratio indicates that the catalyst thickness does not significantly influence the quality of CNTs grown.


2021 ◽  
Vol 19 (11) ◽  
pp. 95-101
Author(s):  
Athraa Mohamed Rashed ◽  
Abdulqadier Hussien Al Khazraji

In this study the normal and activated charcoal were used to prepare normal and activated multi walled carbon nanotubes (MWCNTs) from same plant (Citrus aurantium) which is a source of carbon by Chemical Flame Deposition method (CFDM). The obtained products were analyzed using FESEM, FTIR, XRD, and Raman spectroscopy. The FESEM image of normal charcoal revealed that it has much less nanopores than activated charcoal. The ratios of ID/IG for the normal and activated MWCNTs were 0.85 and 0.91 respectively, which shows that use activated charcoal as a source enhance the disorder and the defects on the carbon nanotubes. The results demonstrate and confirmed that a carbon nanotubes which were prepared from normal and activated charcoal have some disfigurements and have converging diameter nearly (31-88 nm) and (37-70nm) for normal and activated MWCNTs with length about (1-2) μm respectively.


2008 ◽  
Vol 55-57 ◽  
pp. 537-540 ◽  
Author(s):  
U. Rinzin ◽  
Pisith Singjai ◽  
P. Wilairat ◽  
S. Meejoo

Ni catalyst was removed from as received multi-walled Carbon Nanotubes (MWNTs) by acid treatment. Then, the nanotubes were treated with 4M HCl during a ball milling processing yielding mechanochemical treated MWNTs (mech-MWNTs). TEM micrographs indicate that the mech-MWNTs were still of a tubular form but with much shorter length. The equilibrium adsorption of metal ions, e.g Cu2+ and Ni2+, on the mech-MWNTs was investigated at room temperature. The adsorption isotherms gave excellent consistence with the Langmuir theory and the best fit values of K-1 and Κmax can be evaluated using non-linear least-squares. As results, the maximum of Cu2+ and Ni2+ ions uptake on to the mech-MWNTs are 0.93 ± 0.004 mg/g and 2.11 ± 0.01 mg/g respectively. There is no evidence indicating that the pore structure and layer surfaces at both ends of the mech-MWNTs are appropriate sites for metal ions adsorption.


2010 ◽  
Vol 71 ◽  
pp. 34-39
Author(s):  
L. Minati ◽  
G. Speranza ◽  
I. Bernagozzi ◽  
S. Torrengo ◽  
L. Toniutti ◽  
...  

Multi-walled carbon nanotubes were chemically cut by acid treatments and then deposited on 2-aminoethanethiol-modified gold substrate by the application of an external electric field. 2-aminoethanethiol-capped gold nanoparticles were then covalently bonded to the nanotubes to exploit their plasmon resonances. Reaction intermediates as well as the final products were analyzed by X-Ray Photoelectron Spectroscopy, Atomic Force Microscopy and Scanning Electron Microscopy. The synergetic interaction between carbon nanotubes and gold nanoparticles leads to an efficient signal enhancement in Raman spectra. This is of particular interest for the detection of toxic molecules dangerous for the environment.


2011 ◽  
Vol 12 (2) ◽  
pp. 102-106 ◽  
Author(s):  
Young-Soo Park ◽  
Mong-Young Huh ◽  
Sin-Jae Kang ◽  
Seung-Hee Lee ◽  
Kay-Hyeok An

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