Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study

Autores
Bolzán, Agustín Eduardo; Arvia, Alejandro Jorge
Año de publicación
2008
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on polycrystalline gold in aqueous acid solutions is studied by Fourier-transformed infrared reflection absorption spectroscopy (FTIRRAS) and voltammetry. The potential ranges for different electrochemical processes, including electrodissolution of gold and electro-oxidation of thioureas, are determined by cyclic voltammetry. The gradual depletion of thioureas and the progressive formation of products from adsorbed and soluble species in the thin solution layer in contact with the electrode are followed through changes in band intensity of infrared (IR) spectra. Adsorbates of thioureas are formed at 0.05 Vand remain on the surface up to E=1.2 V, a potential at which their electro-oxidation takes place. Irrespective of the type of thiourea, the first electro-oxidation process from soluble thioureas starts at ca. 0.45 V with the formation of their respective disulphide. This process is preceded by the electrodissolution of gold via the formation of gold–thiourea soluble complex species. From ca. 1.2 V upwards the second electro-oxidation process results in the formation of carbon dioxide, sulphate ions and C≡N-containing species. The latter are produced only from N-alkyl thioureas, in which the presence of free amine groups makes the formation of a C≡N bond possible, as a previous stage to the production of carbon dioxide and sulphate ions as final products. From the correlation between voltammetric and spectroscopic data a general reaction pathway for the adsorption of thioureas and their electro-oxidation on gold is advanced.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Materia
Ciencias Exactas
Química
Methylthiourea
Dimethylthiourea
Ethylthiourea
Diethylthiourea
Electro-oxidation
Adsorbates
Gold electrode
FTIRRAS
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/119002
Acceder
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oai_identifier_str oai:sedici.unlp.edu.ar:10915/119002
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry studyBolzán, Agustín EduardoArvia, Alejandro JorgeCiencias ExactasQuímicaMethylthioureaDimethylthioureaEthylthioureaDiethylthioureaElectro-oxidationAdsorbatesGold electrodeFTIRRASThe adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on polycrystalline gold in aqueous acid solutions is studied by Fourier-transformed infrared reflection absorption spectroscopy (FTIRRAS) and voltammetry. The potential ranges for different electrochemical processes, including electrodissolution of gold and electro-oxidation of thioureas, are determined by cyclic voltammetry. The gradual depletion of thioureas and the progressive formation of products from adsorbed and soluble species in the thin solution layer in contact with the electrode are followed through changes in band intensity of infrared (IR) spectra. Adsorbates of thioureas are formed at 0.05 Vand remain on the surface up to E=1.2 V, a potential at which their electro-oxidation takes place. Irrespective of the type of thiourea, the first electro-oxidation process from soluble thioureas starts at ca. 0.45 V with the formation of their respective disulphide. This process is preceded by the electrodissolution of gold via the formation of gold–thiourea soluble complex species. From ca. 1.2 V upwards the second electro-oxidation process results in the formation of carbon dioxide, sulphate ions and C≡N-containing species. The latter are produced only from N-alkyl thioureas, in which the presence of free amine groups makes the formation of a C≡N bond possible, as a previous stage to the production of carbon dioxide and sulphate ions as final products. From the correlation between voltammetric and spectroscopic data a general reaction pathway for the adsorption of thioureas and their electro-oxidation on gold is advanced.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas2008info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf529–543http://sedici.unlp.edu.ar/handle/10915/119002enginfo:eu-repo/semantics/altIdentifier/issn/1433-0768info:eu-repo/semantics/altIdentifier/issn/1432-8488info:eu-repo/semantics/altIdentifier/doi/10.1007/s10008-007-0447-5info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-10-22T17:08:56Zoai:sedici.unlp.edu.ar:10915/119002Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-22 17:08:56.351SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
title Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
spellingShingle Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
Bolzán, Agustín Eduardo
Ciencias Exactas
Química
Methylthiourea
Dimethylthiourea
Ethylthiourea
Diethylthiourea
Electro-oxidation
Adsorbates
Gold electrode
FTIRRAS
title_short Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
title_full Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
title_fullStr Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
title_full_unstemmed Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
title_sort Adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on gold electrodes in acid solutions. A combined FTIRRAS and voltammetry study
dc.creator.none.fl_str_mv Bolzán, Agustín Eduardo
Arvia, Alejandro Jorge
author Bolzán, Agustín Eduardo
author_facet Bolzán, Agustín Eduardo
Arvia, Alejandro Jorge
author_role author
author2 Arvia, Alejandro Jorge
author2_role author
dc.subject.none.fl_str_mv Ciencias Exactas
Química
Methylthiourea
Dimethylthiourea
Ethylthiourea
Diethylthiourea
Electro-oxidation
Adsorbates
Gold electrode
FTIRRAS
topic Ciencias Exactas
Química
Methylthiourea
Dimethylthiourea
Ethylthiourea
Diethylthiourea
Electro-oxidation
Adsorbates
Gold electrode
FTIRRAS
dc.description.none.fl_txt_mv The adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on polycrystalline gold in aqueous acid solutions is studied by Fourier-transformed infrared reflection absorption spectroscopy (FTIRRAS) and voltammetry. The potential ranges for different electrochemical processes, including electrodissolution of gold and electro-oxidation of thioureas, are determined by cyclic voltammetry. The gradual depletion of thioureas and the progressive formation of products from adsorbed and soluble species in the thin solution layer in contact with the electrode are followed through changes in band intensity of infrared (IR) spectra. Adsorbates of thioureas are formed at 0.05 Vand remain on the surface up to E=1.2 V, a potential at which their electro-oxidation takes place. Irrespective of the type of thiourea, the first electro-oxidation process from soluble thioureas starts at ca. 0.45 V with the formation of their respective disulphide. This process is preceded by the electrodissolution of gold via the formation of gold–thiourea soluble complex species. From ca. 1.2 V upwards the second electro-oxidation process results in the formation of carbon dioxide, sulphate ions and C≡N-containing species. The latter are produced only from N-alkyl thioureas, in which the presence of free amine groups makes the formation of a C≡N bond possible, as a previous stage to the production of carbon dioxide and sulphate ions as final products. From the correlation between voltammetric and spectroscopic data a general reaction pathway for the adsorption of thioureas and their electro-oxidation on gold is advanced.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
description The adsorption and electro-oxidation of N-alkyl and N,N’-dialkyl thioureas on polycrystalline gold in aqueous acid solutions is studied by Fourier-transformed infrared reflection absorption spectroscopy (FTIRRAS) and voltammetry. The potential ranges for different electrochemical processes, including electrodissolution of gold and electro-oxidation of thioureas, are determined by cyclic voltammetry. The gradual depletion of thioureas and the progressive formation of products from adsorbed and soluble species in the thin solution layer in contact with the electrode are followed through changes in band intensity of infrared (IR) spectra. Adsorbates of thioureas are formed at 0.05 Vand remain on the surface up to E=1.2 V, a potential at which their electro-oxidation takes place. Irrespective of the type of thiourea, the first electro-oxidation process from soluble thioureas starts at ca. 0.45 V with the formation of their respective disulphide. This process is preceded by the electrodissolution of gold via the formation of gold–thiourea soluble complex species. From ca. 1.2 V upwards the second electro-oxidation process results in the formation of carbon dioxide, sulphate ions and C≡N-containing species. The latter are produced only from N-alkyl thioureas, in which the presence of free amine groups makes the formation of a C≡N bond possible, as a previous stage to the production of carbon dioxide and sulphate ions as final products. From the correlation between voltammetric and spectroscopic data a general reaction pathway for the adsorption of thioureas and their electro-oxidation on gold is advanced.
publishDate 2008
dc.date.none.fl_str_mv 2008
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/119002
url http://sedici.unlp.edu.ar/handle/10915/119002
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/1433-0768
info:eu-repo/semantics/altIdentifier/issn/1432-8488
info:eu-repo/semantics/altIdentifier/doi/10.1007/s10008-007-0447-5
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
529–543
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
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reponame_str SEDICI (UNLP)
collection SEDICI (UNLP)
instname_str Universidad Nacional de La Plata
instacron_str UNLP
institution UNLP
repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
repository.mail.fl_str_mv alira@sedici.unlp.edu.ar
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