Soft-x-ray photoemission spectroscopy and ab initio studies on the adsorption of NO2 molecules on defective multiwalled carbon nanotubes

I Lozzi; S Picozzi; L Armentano; L Valentini; J M Kenny; S La Rosa; M Coreno; M de Simone; B Delley; S Santucci

doi:10.1063/1.1947768

Soft-x-ray photoemission spectroscopy and ab initio studies on the adsorption of NO2 molecules on defective multiwalled carbon nanotubes

J Chem Phys. 2005 Jul 15;123(3):34702. doi: 10.1063/1.1947768.

Authors

I Lozzi¹, S Picozzi, L Armentano, L Valentini, J M Kenny, S La Rosa, M Coreno, M de Simone, B Delley, S Santucci

Affiliation

¹ Istituto Nazionale per la Fisica della Materia-Consiglio Nazionale delle Ricerche (INFM-CNR) and Department of Physics, University of L'Aquila, Coppito, Italy. [email protected]

PMID: 16080750
DOI: 10.1063/1.1947768

Abstract

The adsorption of NO(2) molecules on defective multiwalled carbon nanotubes has been studied by soft-x-ray photoemission. The valence band and carbon core-level spectra have been acquired before, during, and after NO(2) exposure. The spectra show a reversible decrease of the density of states at the top of the valence band when NO(2) molecules are adsorbed on the (carbon nanotubes) CNTs. No shift of the C 1s spectra has been observed. Theoretical calculations, using density-functional theory, have been performed on the CNT + NO(2) system, considering semiconducting nanotubes with different diameters and introducing a Stone-Wales [Chem. Phys. Lett. 128, 501 (1986)] defect. The calculation confirms the decrease of the density of states at the top of the valence band in the CNT + NO(2) system, while close to the adsorption site new states appear very close to the Fermi level.