Intermetallic catalyst for carbon nanotubes (CNTs) growth by thermal chemical vapor deposition method

被引:170
作者
Chen, Chia-Ming
Dai, Yong-Ming
Huang, Jenn Gwo
Jehng, Jih-Mirn [1 ]
机构
[1] Natl Chung Hsing Univ, Dept Chem Engn, Taichung 402, Taiwan
[2] Chien Kuo Technol Univ, Dept Elect Engn, Changhua 500, Taiwan
关键词
carbon nanotubes; chemical vapor deposition; X-ray diffraction; Raman spectroscopy; carbon yield;
D O I
10.1016/j.carbon.2005.12.043
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The methane conversion and carbon yield of the chemical vapor deposition (CVD) reaction suggests that the optimum reaction conditions of the formation of multi-wall carbon nanotubes (MWCNTs) can be obtained by using a 50 mg of nano-MgNi alloy under pyrolysis of the pure CH4 gas with the flow rate about 100-120 cm(3)/min at 650 degrees C for 30 min. Raman results indicate the CNTs are in multi-wall structure, since no single-wall characteristic features appearing in the 200-400 cm(-1) region. This is consistent with those of the XRD and TGA findings. Under selected condition, the carbon yield and the CNTs purity can reach up to 1231% and 92% in the presence of hydrogen. It is presumable that the presence of hydrogen in the pyrolysis of CH4 prevents the deactivation of catalysts and enhances the graphitization degree of CNTs. In addition, the presence of Mg metal in the alloy can prevent the aggregation of the Ni metal and forms the active Mg2Ni phase to enhance the CH4 Pyrolysis to form CNTs. After the purification procedures with both air oxidation at 550 degrees C and HCl treatments, the final purified yield and purity of CNT reach to 73.2% and (98.04 +/- 0.2)% respectively. (C) 2006 Elsevier Ltd. All rights reserved.
引用
收藏
页码:1808 / 1820
页数:13
相关论文
共 62 条
[51]   Purification of single-wall carbon nanotubes [J].
Shi, ZJ ;
Lian, YF ;
Liao, FH ;
Zhou, XH ;
Gu, ZN ;
Zhang, YG ;
Iijima, S .
SOLID STATE COMMUNICATIONS, 1999, 112 (01) :35-37
[52]   HYDROGENATION OF ETHYLENE OVER LANI5H3.3 [J].
SOGA, K ;
IMAMURA, H ;
IKEDA, S .
CHEMISTRY LETTERS, 1976, (12) :1387-1388
[53]   Mechanical alloying and milling [J].
Suryanarayana, C .
PROGRESS IN MATERIALS SCIENCE, 2001, 46 (1-2) :1-184
[54]   TOPOGRAPHICAL STUDIES OF OXIDIZED GRAPHITE SURFACES - A SUMMARY OF PRESENT POSITION [J].
THOMAS, JM .
CARBON, 1969, 7 (03) :359-&
[55]   CARBON - AN OLD BUT NEW MATERIAL REVISITED [J].
WALKER, PL .
CARBON, 1990, 28 (2-3) :261-279
[56]   Extended milling of graphite and activated carbon [J].
Welham, NJ ;
Williams, JS .
CARBON, 1998, 36 (09) :1309-1315
[57]  
WUENBERG WH, 1974, SURF SCI, V41, P312
[58]   Structure and oxidation patterns of carbon nanotubes [J].
Yao, N ;
Lordi, V ;
Ma, SXC ;
Dujardin, E ;
Krishnan, A ;
Treacy, MMJ ;
Ebbesen, TW .
JOURNAL OF MATERIALS RESEARCH, 1998, 13 (09) :2432-2437
[59]   Strength and breaking mechanism of multiwalled carbon nanotubes under tensile load [J].
Yu, MF ;
Lourie, O ;
Dyer, MJ ;
Moloni, K ;
Kelly, TF ;
Ruoff, RS .
SCIENCE, 2000, 287 (5453) :637-640
[60]   Single-wall carbon nanotube formation by laser ablation using double-targets of carbon and metal [J].
Yudasaka, M ;
Komatsu, T ;
Ichihashi, T ;
Iijima, S .
CHEMICAL PHYSICS LETTERS, 1997, 278 (1-3) :102-106