A novel CW laser-powder method of carbon single-wall nanotubes production

A novel continuous high productive laser-powder method of carbon single-wall nanotube (SWNT) synthesis based on the laser ablation of mixed graphite and metallic catalysts (Ni/Co = 1:1) powders by a 2-kW continuous wave CO2 laser in an argon or nitrogen stream has been proposed. Thermal conductive losses of the laser power introduced in micron-size particles were significantly decreased compared to laser heating of the bulk solid targets in known laser techniques. As a result, more effective utilization of the absorbed laser power for material evaporation was achieved. The carbon soot yield obtained was 5 g/h. Preliminary tests have revealed a SWNT abundance in the soot of 20-40% with a mean diameter of 1.2-1.3 nm as established by Raman spectroscopy and HRTEM. Approaches for the enrichment of the soot with nanotubes are considered. (C) 2002 Elsevier Science B.V. All rights reserved.