Article Title

In Situ TEM observation of the gasification and growth of carbon nanotubes using iron catalysts

Authors

Xiaofeng Feng, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China Present address: Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA
See Wee Chee, Leroy Eyring Center for Solid State Science, Arizona State University, Tempe, AZ 85287, USA Present Address: Department of Materials Science and Engineerig, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
Renu Sharma, Leroy Eyring Center for Solid State Science, Arizona State University, Tempe, AZ 85287, USA Present address: National Institute of Science and Technology, Gaithersburg, MD 20899, USA
Kai Liu, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
Xu Xie, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China Present address: Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
Qunqing Li, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
Shoushan Fan, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
Kaili Jiang, Department of Physics and Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China

Keywords

Carbon nanotubes, gasification, growth, iron catalyst, environmental transmission electron microscopy (ETEM), thermogravimetric analysis (TGA)

Abstract

ABSTRACT We report the in situ transmission electron microscope (TEM) observation of the catalytic gasification and growth of carbon nanotubes (CNTs). It was found that iron catalysts can consume the CNTs when pumping out the precursor gas, acetylene, at the growth temperature, and reinitiate the growth when acetylene is re-introduced. The switching between gasification and growth of CNTs can be repeated many times with the same catalyst. To understand the phenomenon, thermogravimetric analysis (TGA) coupled with mass spectroscopy was used to study the mechanism involved. It was shown that the residual water molecules in the growth chamber of the TEM react with and remove carbon atoms of CNTs as carbon monoxide vapor under the action of the catalyst, when the precursor gas is pumped out. This result contributes to a better understanding of the water-assisted and oxygen-assisted synthesis of CNT arrays, and provides useful clues on how to extend the lifetime and improve the activity of the catalysts.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-011-0133-x

Publisher

Tsinghua University Press

Recommended Citation

Xiaofeng Feng,See Wee Chee,Renu Sharma,Kai Liu,Xu Xie,Qunqing Li,Shoushan Fan,Kaili Jiang, In Situ TEM observation of the gasification and growth of carbon nanotubes using iron catalysts. NanoRes.2011, 4(8): 767–779