High yield production of defect less carbon nanotubes in an arc process

An efficient modified arc plasma method, where a focusing electric field is superimposed on the arc electric field, is optimized for the bulk generation of highly pure multi-walled carbon nanotubes (MWNTs). Raman spectroscopy and thermogravimetric measurements have been used to optimize the process. It was found that, at the optimized focusing field configuration, this process can utilize about 85% of the consumed anode material as compared to about 35% in the conventional arc plasma method. The sample prepared at the optimized conditions exhibited negligible D band intensity along with a reduced line width (14cm-1) of the G band in the Raman spectrum. The oxidation temperature of this