A comparative study of the electronic structures of oxygen- and chlorine- treated nitrogenated carbon nanotubes by x-ray absorption and scanning photoelectron microscopy

摘要

The electronic structures and bonding properties of oxygen- and chlorine-treated nitrogenated carbon nanotubes (N-CNTs) were studied using x-ray absorption near-edge structure (XANES) and scanning photoelectron microscopy. Features in the C Κ-edge XANES spectra are shifted by ～0.3 eV toward higher energies and by ～1.1 eV toward lower energies relatively to those of the more symmetrical pyridinelike and graphitelike structured N-CNTs upon chlorination and oxidation, respectively. Increases in N Κ-edge XANES intensities for both chlorination and oxidation reveal substitution of C-C bonds by C-N bonds consistent with the observed valence-band photoemission spectra of the decrease of the C 2s bond and the increase of the N 2s bond.