Preparation of carbon nanotubes by DC arc discharge process under reduced pressure in an air atmosphere

Carbon nanotubes (CNTs) were grown using a DC arc discharge process in an air atmosphere and relevant process parameters were investigated. ithout using an inert gas, multi walled carbon nanotubes could be synthesized in the deposit area of the cathode even in an air atmosphere, but ingle walled carbon nanotubes were not detected in the soot area despite using the same process conditions as in the inert gas. The air pressure for he highest yield of multi walled CNTs was 300 Torr. In addition, the quantity of amorphous carbon and other nanoparticles in the process chamber as remarkably reduced by this technique, showing that an efficient, feasible method of large scale CNT fabrication could be achieved by the arc ischarge process. 2006 Elsevier B.V. All rights reserved.