In situ TA-MS study of the six-membered-ring-based growth of carbon nanotubes with benzene precursor.
By using the in situ thermal analysis-mass spectroscopic technique, combined with transmission electron microscopic characterization of the carbon nanotube (CNT) product, we have studied the chemical vapor deposition (CVD) growth of CNTs with Fe-Co/gamma-Al2O3 catalyst and benzene precursor in the range of room temperature to 700 degrees C. The growth process has been clearly illuminated, which starts from the reduction of catalyst around 645 degrees C followed by the dissociation of carbon-hydrogen bonds of benzene and the sequential growth of CNTs. A surprising fact is that no possible hydrocarbon species derived from benzene was detected, indicating that the carbon-carbon bond was not broken under our experimental conditions. All of the experimental results strongly reinforce the six-membered-ring-based growth model, and a schematic elucidation is presented accordingly. This in situ study not only reveals the unique and convincing information directly related to the growth mechanism from the involved chemistry, but also provides a powerful way to clarify the mechanism of CVD synthesis of CNTs with other precursors.
Tian
Yajun
Y
Key Lab of Mesoscopic Chemistry and Jiangsu Provincial Laboratory for NanoTechnology, Department of Chemistry, Nanjing University, Nanjing 210093, China.
Hu
Zheng
Z
Yang
Yong
Y
Wang
Xizhang
X
Chen
Xin
X
Xu
Hua
H
Wu
Qiang
Q
Ji
Weijie
W
Chen
Yi
Y