Efficient laser synthesis of single-walled carbon nanotubes through laser heating of the condensing vaporization plume

Significant improvement in the production rate of high-purity single-walled carbon nanotubes using the laser-oven method is reported. The effects of using continuous wave (cw) and kilohertz frequency Nd:YAG lasers at 1064 nm as well as a cw argon ion laser at 514.5 nm to excite the vaporized plume during the pulsed-laser synthesis of single-walled carbon nanotubes have been studied. Production rates exceeding 400 mg/h of nanotube deposits have been achieved. Raman spectroscopy, transmission electron microscopy, isothermal gas adsorption and thermo-gravimetric analysis indicate single-walled nanotube purity approaching 80% and metal catalyst contamination of less than 6% by weight. Gas adsorption measurements using nitrogen and argon have been performed to help characterize the bundle structure of the SWNT. Possible insights into the nanotube synthesis mechanism have been discussed. Crown Copyright (C) 2004 Published by Elsevier Ltd. All rights reserved.