A Rapid and Simple Homogenizing Method for the Purification of Single-walled Carbon Nanotubes

We developed a simple and effective purification method to obtain high-purity single-walled carbon nanotubes (SWCNTs) with low surface damage. The purification process consists of oxidization at $430^{\circ}C$ for 1 h in a furnace system of air atmosphere and homogenization in dilute hydrochloric acid solution for extremely short time. The role of homogenizer was examined during purification process in terms of purity and quality of purified SWCNTs. High-purity and low surface damage of SWCNT products was obtained using homogenizer which was operated at 8500 rpm for 10 min in the environment of 7 % HCI solution. From XRD spectra, we observed that metal catalysts were thoroughly removed. Raman spectra showed that the intensity values of crystallization ($I_{G}/I_{D}$) of purified SWCNTs were very similar with that of pristine SWCNTs. Moreover, the structure damage of purified SWCNTs was hard to find from electron microscopy. Consequently, homogenizing, which is a quick and simple manner, can be promising method for obtaining final SWCNTs with clearly high purity and crystallinity.