A simple purification for single-walled carbon nanotubes

A simple, effective and non-destructive purification process for single-walled carbon nanotubes synthesized by arc discharge has been demonstrated in this paper. The by-products, amorphous carbon, multi-walled graphite and metallic catalyst, were eliminated successfully by a combination of ultrasonication in the presence of surfactant and gas oxidation. The oxidation in oxygen is advantageous against wet chemical methods because it is easily controllable. Thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Raman spectroscopy were used to investigate the changes of single-walled carbon nanotubes (SWNT). The purity and yield of SWNT are improved due to reduced impurities stuck to the SWNT.