Yang Jiang, Yue Wu, Shuyuan Zhang, Cunyi Xu, Weichao Yu, Yi Xie, Yitai Qian
School of Chemistry and Materials Science, USTC
The 2001 Second-Class National Natural Science Award
The discovery of carbon nanotube has become a very hot research area in the world. Based on the syntheses method of carbon nanotube in solution, hexachorobenzene with plane hexagonal carbon structure was used to prepare graphite-like compounds in chemical liquid systems. The benzenethermal route was developed to obtain multiwall carbon nanotubes using the reduction of hexachorobenzene by metallic potassium in the presence of Co/Ni catalyzer at 350?ムafter 8h. A catalytic-assembly mechanism of plane hexagonal carbon clusters was proposed. Fig.1 shows the diagrammatical scheme for the formation of carbon nanotube and Fig. 2 displays the TEM and HRTEM graphs for the multiwall carbon nanotubes.
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The yield of multiwall carbon nanotubes is about 10% estimated by the observation from TEM graphs. Individual carbon nanotube can be observed in the present experiment, which will be very important to operate or employ the carbon nanotube in practical applications. In addition, different formation mechanisms for multi-or single-wall carbon nanotubes have been proven by present experiments which will be helpful for further studying the formation mechanism of two kinds of carbon nanotubes.
Fig. 1 The scheme of the catalytic-assembly benzenethermal route to multiwall carbon nanotubes.
Fig.2 The TEM (a, b) and HRTEM (c) images of multiwall carbon nanotubes
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