Hydrothermal purification and surface modification of single-walled carbon nanotubes

Purification and modification of single-walled carbon nanotubes (SWCNTs) have been performed by using hydrothermal and chemical treatments at the same time. The effect of these treatments is examined by using Raman spectroscopy, scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy, transition electron microscopy (TEM), and infrared spectroscopy (FT-IR) to characterize the intermediate products. A combination of Raman spectroscopy and morphology analyses indicate that almost all graphite nanoparticles and metals are washed out of the SWCNTs after purification. FT-IR shows that the SWCNTs are functionalized by attaching oxygen functional groups to chemical bonds, leading to a modification of the physicochemical properties of the SWCNTs.