A systematic characterization of single-walled carbon nanotubes (SWCNTs) after successive purification steps
including air oxidation at 350℃
hydrochloric acid etching and 600℃ annealing in Ar
have been performed combining X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS).The results indicated that the modification degree of SWCNTs increased after the purification procedures
but decreased significantly by annealing in Ar.It also showed that the SWCNTs could bond with chlorine atoms during the hydrochloric acid etching and suggested this modification may be importance for the applications.