Evidence for, and an understanding of, the initial nucleation of carbon nanotubes produced by a floating catalyst method.
Evidence for, and an understanding of, the initial nucleation of carbon nanotubes produced by a floating catalyst method.
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DOI：
10.1021/jp062526x
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发表时间：
2006-08
期刊：
影响因子：
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通讯作者：
W. Ren;Feng Li;Hui‐Ming Cheng
中科院分区：
文献类型：
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作者：
W. Ren;Feng Li;Hui‐Ming Cheng
了解碳纳米管（CNTs）的生长机理对于控制其结构具有重要意义，这将为进一步的理论研究和应用奠定基础。通过高分辨透射电镜对碳纳米管初始成核过程的观察，得出以下结论：（1）单壁碳纳米管（SWNTs）和双壁碳纳米管（DWNTs）的成核起始于反应区前面的低温区;（2）硫的加入使大颗粒催化剂表面形成局部液相区，作为初始成核点;（3）温度梯度是实现硫在CNT结构中的作用所必需的;以及（4）CNT的壳数可以在成核和生长阶段改变。在此基础上，提出了单壁碳纳米管和双壁碳纳米管的生长模型，为控制碳纳米管的结构提供了可能。
An understanding of the growth mechanism of carbon nanotubes (CNTs) is very important for the control of their structures, which in turn will be the basis for their further theoretical studies and applications. On the basis of high-resolution transmission electron microscopy observations of the initial nucleation of CNTs, the following deductions are made: (1) the nucleation of single-walled carbon nanotubes (SWNTs) and double-walled carbon nanotubes (DWNTs) starts at a low-temperature zone in front of the reaction zone; (2) the addition of sulfur results in localized liquid zones on the surface of big catalyst particles as the initial nucleation sites; (3) a temperature gradient is necessary to realize the role of sulfur in the structure of CNTs; and (4) the shell number of CNTs can be changed at the nucleation and growth stages. On the basis of the above, a growth model for the formation of SWNTs and DWNTs is proposed, which might open up the possibility of controlling the structure of CNTs.