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Electronic structure of fluorinated multiwalled carbon nanotubes studied using x-ray absorption and photoelectron spectroscopy

Brzhezinskaya, M. M.; Muradyan, V. E.; Vinogradov, N. A.; Preobrajenski, Alexei LU ; Gudat, W. and Vinogradov, A. S. (2009) In Physical Review B (Condensed Matter and Materials Physics) 79(15).
Abstract
This paper presents the results of combined investigation of the chemical bond formation in fluorinated multiwalled carbon nanotubes (MWCNTs) with different fluorine contents (10-55 wt %) and reference compounds (highly oriented pyrolytic graphite crystals and "white" graphite fluoride) using x-ray absorption and photoelectron spectroscopy at C 1s and F 1s thresholds. Measurements were performed at BESSY II (Berlin, Germany) and MAX-laboratory (Lund, Sweden). The analysis of the soft x-ray absorption and photoelectron spectra points to the formation of covalent chemical bonding between fluorine and carbon atoms in the fluorinated nanotubes. It was established that within the probing depth (similar to 15 nm) of carbon nanotubes, the process... (More)
This paper presents the results of combined investigation of the chemical bond formation in fluorinated multiwalled carbon nanotubes (MWCNTs) with different fluorine contents (10-55 wt %) and reference compounds (highly oriented pyrolytic graphite crystals and "white" graphite fluoride) using x-ray absorption and photoelectron spectroscopy at C 1s and F 1s thresholds. Measurements were performed at BESSY II (Berlin, Germany) and MAX-laboratory (Lund, Sweden). The analysis of the soft x-ray absorption and photoelectron spectra points to the formation of covalent chemical bonding between fluorine and carbon atoms in the fluorinated nanotubes. It was established that within the probing depth (similar to 15 nm) of carbon nanotubes, the process of fluorination runs uniformly and does not depend on the fluorine concentration. In this case, fluorine atoms interact with MWCNTs through the covalent attachment of fluorine atoms to graphene layers of the graphite skeleton (phase 1) and this bonding is accompanied by a change in the hybridization of the 2s and 2p valence electron states of the carbon atom from the trigonal (sp(2)) to tetrahedral (sp(3)) hybridization and by a large electron transfer between carbon an fluorine atoms. In the MWCNT near-surface region the second fluorine-carbon phase with weak electron transfer is formed; it is located mainly within two or three upper graphene monolayers, and its contribution becomes much poorer as the probing depth of fluorinated multiwalled carbon nanotubes (F-MWCNTs) increases. The defluorination process of F-MWCNTs on thermal annealing has been investigated. The conclusion has been made that F-MWCNT defluorination without destruction of graphene layers is possible. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
absorption spectra, X-ray, fluorine, carbon nanotubes, band structure, bonds (chemical), X-ray photoelectron spectra
in
Physical Review B (Condensed Matter and Materials Physics)
volume
79
issue
15
publisher
American Physical Society
external identifiers
  • wos:000265944200128
  • scopus:66149185548
ISSN
1098-0121
DOI
10.1103/PhysRevB.79.155439
language
English
LU publication?
yes
id
fb94e0c9-3b72-4546-8ed7-fec6897adce6 (old id 1425847)
date added to LUP
2009-06-26 15:10:09
date last changed
2017-09-24 03:59:46
@article{fb94e0c9-3b72-4546-8ed7-fec6897adce6,
  abstract     = {This paper presents the results of combined investigation of the chemical bond formation in fluorinated multiwalled carbon nanotubes (MWCNTs) with different fluorine contents (10-55 wt %) and reference compounds (highly oriented pyrolytic graphite crystals and "white" graphite fluoride) using x-ray absorption and photoelectron spectroscopy at C 1s and F 1s thresholds. Measurements were performed at BESSY II (Berlin, Germany) and MAX-laboratory (Lund, Sweden). The analysis of the soft x-ray absorption and photoelectron spectra points to the formation of covalent chemical bonding between fluorine and carbon atoms in the fluorinated nanotubes. It was established that within the probing depth (similar to 15 nm) of carbon nanotubes, the process of fluorination runs uniformly and does not depend on the fluorine concentration. In this case, fluorine atoms interact with MWCNTs through the covalent attachment of fluorine atoms to graphene layers of the graphite skeleton (phase 1) and this bonding is accompanied by a change in the hybridization of the 2s and 2p valence electron states of the carbon atom from the trigonal (sp(2)) to tetrahedral (sp(3)) hybridization and by a large electron transfer between carbon an fluorine atoms. In the MWCNT near-surface region the second fluorine-carbon phase with weak electron transfer is formed; it is located mainly within two or three upper graphene monolayers, and its contribution becomes much poorer as the probing depth of fluorinated multiwalled carbon nanotubes (F-MWCNTs) increases. The defluorination process of F-MWCNTs on thermal annealing has been investigated. The conclusion has been made that F-MWCNT defluorination without destruction of graphene layers is possible.},
  articleno    = {155439},
  author       = {Brzhezinskaya, M. M. and Muradyan, V. E. and Vinogradov, N. A. and Preobrajenski, Alexei and Gudat, W. and Vinogradov, A. S.},
  issn         = {1098-0121},
  keyword      = {absorption spectra,X-ray,fluorine,carbon nanotubes,band structure,bonds (chemical),X-ray photoelectron spectra},
  language     = {eng},
  number       = {15},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Electronic structure of fluorinated multiwalled carbon nanotubes studied using x-ray absorption and photoelectron spectroscopy},
  url          = {http://dx.doi.org/10.1103/PhysRevB.79.155439},
  volume       = {79},
  year         = {2009},
}