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

Abstract

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.