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Adsorption of L-cysteine on rutile TiO2(110)

Ataman, Evren LU ; Isvoranu, Cristina LU ; Knudsen, Jan LU ; Schulte, Karina LU ; Andersen, Jesper N LU and Schnadt, Joachim LU (2011) In Surface Science 605(1-2). p.179-186
Abstract
We have used X-ray photoelectron spectroscopy to study the adsorption of L-cysteine on a rutile TiO2(110) surface at room temperature and -65 degrees C. For the molecules in direct contact with the surface our results suggest that the molecules bind dissociatively to the fivefold-coordinated Ti atoms of the surface through their deprotonated carboxylic groups. A second, dissociative interaction occurs between the molecular thiol groups and the surface. It is attributed to a dissociative bond to the bridging oxygen vacancies. Most likely, the thiol groups are deprotonated and a bond is formed between the thiolates and defects. In an alternative scenario, the C-S bond is cleaved and atomic sulfur binds to the defects. With regard to the... (More)
We have used X-ray photoelectron spectroscopy to study the adsorption of L-cysteine on a rutile TiO2(110) surface at room temperature and -65 degrees C. For the molecules in direct contact with the surface our results suggest that the molecules bind dissociatively to the fivefold-coordinated Ti atoms of the surface through their deprotonated carboxylic groups. A second, dissociative interaction occurs between the molecular thiol groups and the surface. It is attributed to a dissociative bond to the bridging oxygen vacancies. Most likely, the thiol groups are deprotonated and a bond is formed between the thiolates and defects. In an alternative scenario, the C-S bond is cleaved and atomic sulfur binds to the defects. With regard to the molecular amino groups, they remain neutral at the lowest investigated coverages (0.3-0.5 ML), but already starting from around 0.7 ML nominal coverage protons are being transferred to them. The fraction of protonated amino groups increases with coverage and becomes dominating in multilayers prepared at room temperature and -65 degrees C. In these multilayers the carboxylic groups are deprotonated. (C) 2010 Elsevier B.V. All tights reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
L-cysteine, X-ray photoelectron spectroscopy, Rutile TiO2(110), Amino, acid, Adsorption
in
Surface Science
volume
605
issue
1-2
pages
179 - 186
publisher
Elsevier
external identifiers
  • wos:000286021000026
  • scopus:78649655436
ISSN
0039-6028
DOI
10.1016/j.susc.2010.10.017
language
English
LU publication?
yes
id
86352437-5724-483a-bf9b-4f23bee2d602 (old id 1868825)
date added to LUP
2011-04-19 11:19:52
date last changed
2017-01-01 06:25:47
@article{86352437-5724-483a-bf9b-4f23bee2d602,
  abstract     = {We have used X-ray photoelectron spectroscopy to study the adsorption of L-cysteine on a rutile TiO2(110) surface at room temperature and -65 degrees C. For the molecules in direct contact with the surface our results suggest that the molecules bind dissociatively to the fivefold-coordinated Ti atoms of the surface through their deprotonated carboxylic groups. A second, dissociative interaction occurs between the molecular thiol groups and the surface. It is attributed to a dissociative bond to the bridging oxygen vacancies. Most likely, the thiol groups are deprotonated and a bond is formed between the thiolates and defects. In an alternative scenario, the C-S bond is cleaved and atomic sulfur binds to the defects. With regard to the molecular amino groups, they remain neutral at the lowest investigated coverages (0.3-0.5 ML), but already starting from around 0.7 ML nominal coverage protons are being transferred to them. The fraction of protonated amino groups increases with coverage and becomes dominating in multilayers prepared at room temperature and -65 degrees C. In these multilayers the carboxylic groups are deprotonated. (C) 2010 Elsevier B.V. All tights reserved.},
  author       = {Ataman, Evren and Isvoranu, Cristina and Knudsen, Jan and Schulte, Karina and Andersen, Jesper N and Schnadt, Joachim},
  issn         = {0039-6028},
  keyword      = {L-cysteine,X-ray photoelectron spectroscopy,Rutile TiO2(110),Amino,acid,Adsorption},
  language     = {eng},
  number       = {1-2},
  pages        = {179--186},
  publisher    = {Elsevier},
  series       = {Surface Science},
  title        = {Adsorption of L-cysteine on rutile TiO2(110)},
  url          = {http://dx.doi.org/10.1016/j.susc.2010.10.017},
  volume       = {605},
  year         = {2011},
}