scholarly journals High specific surface area carbon nanotubes from catalytic chemical vapor deposition process

2000 ◽  
Vol 323 (5-6) ◽  
pp. 566-571 ◽  
Author(s):  
R.R. Bacsa ◽  
Ch. Laurent ◽  
A. Peigney ◽  
W.S. Bacsa ◽  
Th. Vaugien ◽  
...  
2014 ◽  
Vol 1586 ◽  
Author(s):  
Ryuhei Yamada ◽  
Yasuhiro Masaki ◽  
Yasuaki Hayashi

ABSTRACTCarbon fine particles including single-walled carbon nanotubes (SWNTs) were synthesized by hot-filament and plasma assisted chemical vapor deposition. Specific surface area was evaluated for carbon fine particles synthesized under optimized conditions along with purified SWNTs and multi-walled carbon nanotubes (MWNTs) for comparison. The value of specific surface area for the synthesized carbon fine particles was smaller than the SWNTs, but larger than the MWNTs. Pore size distribution was analyzed with desorption isotherms by the DH method. Although smaller pores are included in the purified SWNTs than the synthesized carbon fine particles, pores of size larger than several nm were included more in the synthesized carbon fine particles.


2004 ◽  
Vol 108 (34) ◽  
pp. 12718-12723 ◽  
Author(s):  
Revathi Bacsa ◽  
Christophe Laurent ◽  
Ryuta Morishima ◽  
Hiroshi Suzuki ◽  
Mikako Le Lay

2011 ◽  
Vol 364 ◽  
pp. 232-237 ◽  
Author(s):  
S.Y. Lim ◽  
M.M. Norani

Catalyst plays a crucial role in determining the characteristics of carbon nanotubes (CNTs) produced by using thermal catalytic chemical vapor deposition (CVD). It is essential to investigate how the catalyst preparation affects the characteristics of CNTs because certain application demands specific size for optimum performance. This study reports the effect of the types of catalyst and the duration of the catalyst pre-treatment (wet etching time, dry etching time and ball milling) on the diameter of CNTs. The synthesized CNTs samples were characterized by scanning and transmission electron microscopy and Raman spectroscopy. Wet etching (2M hydrofluoric acid) time was varied from 1 to 2.5 hrs and the diameter range was found to be in the range of 23 to 52 nm. The diameter range for CNTs produced for 3 hrs and 5 hrs of dry etching treatment (with ammonia gas) are 38 to 51 nm and 23 to 48 nm, respectively. The diameter size of CNTs produced using Ni (14 to 25 nm) was found to be smaller than Fe (38 to 51 nm). There is a significant decrease in the diameter of CNTs by prolonging the wet etching period. Shorter and curly shaped CNTs can also be obtained by using Ni as the catalyst. Keywords: chemical vapor deposition, carbon nanotubes, catalyst pretreatment


2017 ◽  
Vol 5 (16) ◽  
pp. 4068-4074 ◽  
Author(s):  
Xinliang Li ◽  
Xiaowei Yin ◽  
Meikang Han ◽  
Changqing Song ◽  
Hailong Xu ◽  
...  

Ti3C2TxMXenes modified within situgrown carbon nanotubes (CNTs) are fabricatedviaa simple catalytic chemical vapor deposition (CVD) process.


2021 ◽  
Vol 1036 ◽  
pp. 130-136
Author(s):  
Ting Qun Tan ◽  
Lei Geng ◽  
Yan Lin ◽  
Yan He

In order to prepare carbon nanotubes with high specific surface area, small diameter, low resistivity, high purity and high catalytic activity, the Fe-Mo/Al2O3 catalyst was prepared based on the microreactor. The influence of different Fe/Al molar ratios on the catalyst and the carbon nanotubes prepared was studied through BET, SEM, TEM and other detection methods. Studies have shown that the pore structure of the catalyst is dominated by slit pores at a lower Fe/Al molar ratio. The catalytic activity is the highest when the Fe/Al molar ratio is 1:1, reaching 74.1%. When the Fe/Al molar ratio is 1:2, the catalyst has a higher specific surface area, the maximum pore size is 8.63 nm, and the four-probe resistivity and ash content of the corresponding carbon nanotubes are the lowest. The higher the proportion of aluminum, the higher the specific surface area of the catalyst and the carbon nanotubes, and the finer the diameter of the carbon nanotubes, which gradually tends to relax. The results show that when the Fe/Al molar ratio is 1:2, although the catalytic activity of the catalyst is not the highest, the carbon nanotubes prepared have the best performance.


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