title: Soft-x-ray photoemission spectroscopy and ab initio studies on the adsorption of NO2 molecules on defective multiwalled carbon nanotubes.
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.
authors.affiliation: Istituto Nazionale per la Fisica della Materia-Consiglio Nazionale delle Ricerche (INFM-CNR) and Department of Physics, University of L'Aquila, Coppito, Italy. luca.lozzi@aquila.infn.it
authors.forename: I
authors.initials: I
authors.lastname: Lozzi
authors.forename: S
authors.initials: S
authors.lastname: Picozzi
authors.forename: L
authors.initials: L
authors.lastname: Armentano
authors.forename: L
authors.initials: L
authors.lastname: Valentini
authors.forename: J M
authors.initials: JM
authors.lastname: Kenny
authors.forename: S
authors.initials: S
authors.lastname: La Rosa
authors.forename: M
authors.initials: M
authors.lastname: Coreno
authors.forename: M
authors.initials: M
authors.lastname: de Simone
authors.forename: B
authors.initials: B
authors.lastname: Delley
authors.forename: S
authors.initials: S
authors.lastname: Santucci