EXAMINE THE GAS ABSORPTION PROPERTIES OF SINGLE WALL CARBON NANOTUBE BUNDLES BY X-RAY ABSORPTION TECHNIQUES
Meng-Hung Tsai1, Hong-Ming Lin1, Wen-Li Tsai2
and Yeukuang Hwu2
1 Department of Materials Engineering, Tatung University, Taipei 104, Taiwan, R.O.C.
2 Institute of Physics, Academia Sinica, Nankang, Taipei 115, Taiwan, R. O. C.
The absorption mechanism and electrical properties of Single Wall Carbon Nanotube
bundles (SWCNTs) are examined with high-resolution C K-edge X-ray absorption near-edge
structures (XANES) using the synchrotron radiation facility at NSRRC, Taiwan. The X-ray
absorption experiments show that an effective desorption of oxygen and hydrocarbon from the
surface of SWCNTs can be achieved by evacuating to high vacuum at 500K for several hours. The
p-type behavior of SWCNTs exists in pure CO gas and will become the n-type behavior when
SWCNTs has preadsorbed the oxygen. The experiments also show that the amphoteric property in
electrical behavior of SWCNTs is determined by the oxygen absorption.
full paper (pdf, 166 Kb)