XANES study of multi-walled carbon nanotubes modified by HNO_3 vapor

摘要

A simple, efficient, and practical method for the surface modification of multi-walled carbon nanotubes (MWCNTs) by nitric acid vapor is presented. X-ray absorption near edge structure (XANES) spectroscopy has been applied to study the temperature dependent evolution of the electronic structure of HNO_3 vapor treated MWCNTs. After treatment the formation of oxygen containing functional groups was observed in C K-edge and O K-edge XANES spectra of MWCNTs. Moreover, the degree of oxidation made to MWCNTs can be easily controlled by changing treatment temperature. Compared to the conventional liquid HNO_3 treatment, the advantages of this method should allow effective large-scale production of oxygenated MWCNTs for the applications.