Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)

Alkanethiol adsorption on Ag-adatom-modified Au(111) surfaces is studied by means of electrochemical techniques combined with Auger electron spectroscopy and periodic density functional (DF) calculations. The bimetallic surfaces are prepared by Ag underpotential deposition, and only the alkanethiola...

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Autores principales: Fonticelli, Mariano Hernán, Benitez, Guillermo Alfredo, Carro, P., Azzaroni, Omar, Salvarezza, Roberto Carlos, Gonzalez, S., Torres, D., Illas, F.
Formato: Articulo
Lenguaje:Inglés
Publicado: 2008
Materias:
Ciencias Exactas
Química
adsorption
chemical calculations
gold
lattices
thiolates
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/159804
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-159804
record_format dspace
spelling I19-R120-10915-1598042023-11-06T20:07:25Z http://sedici.unlp.edu.ar/handle/10915/159804 Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111) Fonticelli, Mariano Hernán Benitez, Guillermo Alfredo Carro, P. Azzaroni, Omar Salvarezza, Roberto Carlos Gonzalez, S. Torres, D. Illas, F. 2008 2023-11-06T13:16:55Z en Ciencias Exactas Química adsorption chemical calculations gold lattices thiolates Alkanethiol adsorption on Ag-adatom-modified Au(111) surfaces is studied by means of electrochemical techniques combined with Auger electron spectroscopy and periodic density functional (DF) calculations. The bimetallic surfaces are prepared by Ag underpotential deposition, and only the alkanethiolate high-coverage regime is considered. Alkanethiolate electrodesorption from Ag-modified Au(111) surfaces requires potentials shifted 0.3 eV in the negative direction with respect to the value corresponding to desorption from Au(111) surfaces. In agreement with this experimental result, DF calculations show that alkanethiolates prefer to be laterally adsorbed to Ag adatoms, the interaction energy being 0.3 eV larger than that corresponding to the same thiolate on Au(111). Therefore, it is concluded that alkanethiolates adsorbed on Au are likely to be observed only when the Ag adatom surface density is small enough or all Ag sites are occupied. The preference for alkanethiolate adsorption on adatoms is also found for a model surface containing Au adatoms on Au-(111). This indicates that no significant differences in electrodesorption potentials should be expected between Ag-adatom- and Au-adatom-rich surfaces. These findings and the analysis of experimental results strongly suggest that, under experimental conditions, the Au(111) surface does not exhibit a significant amount of Au adatoms, thus casting reasonable doubts on the adatom reconstruction models proposed for thiolates on Au-(111). Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas Articulo Articulo http://creativecommons.org/licenses/by-nc-nd/4.0/ Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) application/pdf 4557-4563
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Exactas
Química
adsorption
chemical calculations
gold
lattices
thiolates
spellingShingle Ciencias Exactas
Química
adsorption
chemical calculations
gold
lattices
thiolates
Fonticelli, Mariano Hernán
Benitez, Guillermo Alfredo
Carro, P.
Azzaroni, Omar
Salvarezza, Roberto Carlos
Gonzalez, S.
Torres, D.
Illas, F.
Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)
topic_facet Ciencias Exactas
Química
adsorption
chemical calculations
gold
lattices
thiolates
description Alkanethiol adsorption on Ag-adatom-modified Au(111) surfaces is studied by means of electrochemical techniques combined with Auger electron spectroscopy and periodic density functional (DF) calculations. The bimetallic surfaces are prepared by Ag underpotential deposition, and only the alkanethiolate high-coverage regime is considered. Alkanethiolate electrodesorption from Ag-modified Au(111) surfaces requires potentials shifted 0.3 eV in the negative direction with respect to the value corresponding to desorption from Au(111) surfaces. In agreement with this experimental result, DF calculations show that alkanethiolates prefer to be laterally adsorbed to Ag adatoms, the interaction energy being 0.3 eV larger than that corresponding to the same thiolate on Au(111). Therefore, it is concluded that alkanethiolates adsorbed on Au are likely to be observed only when the Ag adatom surface density is small enough or all Ag sites are occupied. The preference for alkanethiolate adsorption on adatoms is also found for a model surface containing Au adatoms on Au-(111). This indicates that no significant differences in electrodesorption potentials should be expected between Ag-adatom- and Au-adatom-rich surfaces. These findings and the analysis of experimental results strongly suggest that, under experimental conditions, the Au(111) surface does not exhibit a significant amount of Au adatoms, thus casting reasonable doubts on the adatom reconstruction models proposed for thiolates on Au-(111).
format Articulo
Articulo
author Fonticelli, Mariano Hernán
Benitez, Guillermo Alfredo
Carro, P.
Azzaroni, Omar
Salvarezza, Roberto Carlos
Gonzalez, S.
Torres, D.
Illas, F.
author_facet Fonticelli, Mariano Hernán
Benitez, Guillermo Alfredo
Carro, P.
Azzaroni, Omar
Salvarezza, Roberto Carlos
Gonzalez, S.
Torres, D.
Illas, F.
author_sort Fonticelli, Mariano Hernán
title Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)
title_short Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)
title_full Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)
title_fullStr Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)
title_full_unstemmed Effect of Ag Adatoms on High-Coverage Alkanethiolate Adsorption on Au(111)
title_sort effect of ag adatoms on high-coverage alkanethiolate adsorption on au(111)
publishDate 2008
url http://sedici.unlp.edu.ar/handle/10915/159804
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