Purification of single-walled carbon nanotubes synthesized by the hydrogen arc-discharge method

A simple procedure for the purification of the single-walled carbon nanotube (SWNT) product synthesized by the hydrogen arc-discharge method was proposed and discussed. The procedure involves ultrasonication in alcohol, oxidation in fixed air, and soaking in hydrochloric acid. Most of the amorphous carbon and carbon nanoparticles as well as metal particles in the product was successfully removed, according to the results obtained from transmission electron microscopy, thermogravimetric analysis, and resonant laser Raman measurements. With this procedure, a 41 wt% yield of the SWNTs with a purity of about 96% was achieved after purification.