Synthesis of Carbon Nanotubes by Laser Ablation of Graphites at Room Temperature

We successfully synthesized carbon nanotubes with very small diameters (5–10 nm) at room temperature by using high energy laser pulses (193 nm, 5 J/cm 2 and 20 ns duration time) to re-excite the carbon species contained in the laser ejected plume. The carbon nanotubes, which presumably formed in gas phase, were preferentially collected by electro-statically biasing (∼ 5 kVDC) the substrates. High resolution transmission electron microscopic analysis reveals that thus obtained materials are multiwall carbon nanotubes.