In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions

Autores
Bolzán, Agustín Eduardo; Iwasita, T.; Arvia, Alejandro Jorge
Año de publicación
2003
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
The electro-oxidation of gold and thiourea (TU) in aqueous acid solutions is investigated by means of in situ FTIRRAS measurements complemented by voltammetry. The formation of soluble species related to the gold(I)-TU complex and TU electrooxidation products is monitored by following the changes in the IR spectra with the applied potential in the range -0.1 -1.5 V. Experimental data show that gold electrodissolution produces soluble [Au(CS(NH2)2)2]2SO4 species. The IR spectrum of solid samples of this complex is reported. The electrodissolution reaction begins at approximately 0.15 V (SHE), concomitantly with the early stages of TU electro-oxidation. The electro-oxidation of TU on gold in acid solutions produces formamidine disulphide (FDS) at potentials below 1.2 V (SHE). The formation of the gold complex and that of FDS are quasi-reversible processes, as revealed by FTIRRAS data. Once the formation of the oxygen-containing layer on gold sets in, the electro-oxidation of TU and FDS yields carbon dioxide, sulphate ions and CN-containing products. Adsorbed sulphate species, which are also detected from 1.2 V upwards, exhibit a band shift of 27 cm-1 V-1.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
Materia
Ciencias Exactas
Química
Thiourea
Electro-oxidation
Formamidine disulphide
FTIRRAS
Gold
Electrodissolution
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/121267
Acceder
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oai_identifier_str oai:sedici.unlp.edu.ar:10915/121267
network_acronym_str SEDICI
repository_id_str 1329
network_name_str SEDICI (UNLP)
spelling In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutionsBolzán, Agustín EduardoIwasita, T.Arvia, Alejandro JorgeCiencias ExactasQuímicaThioureaElectro-oxidationFormamidine disulphideFTIRRASGoldElectrodissolutionThe electro-oxidation of gold and thiourea (TU) in aqueous acid solutions is investigated by means of in situ FTIRRAS measurements complemented by voltammetry. The formation of soluble species related to the gold(I)-TU complex and TU electrooxidation products is monitored by following the changes in the IR spectra with the applied potential in the range -0.1 -1.5 V. Experimental data show that gold electrodissolution produces soluble [Au(CS(NH<sub>2</sub>)<sub>2</sub>)<sub>2</sub>]<sub>2</sub>SO<sub>4</sub> species. The IR spectrum of solid samples of this complex is reported. The electrodissolution reaction begins at approximately 0.15 V (SHE), concomitantly with the early stages of TU electro-oxidation. The electro-oxidation of TU on gold in acid solutions produces formamidine disulphide (FDS) at potentials below 1.2 V (SHE). The formation of the gold complex and that of FDS are quasi-reversible processes, as revealed by FTIRRAS data. Once the formation of the oxygen-containing layer on gold sets in, the electro-oxidation of TU and FDS yields carbon dioxide, sulphate ions and CN-containing products. Adsorbed sulphate species, which are also detected from 1.2 V upwards, exhibit a band shift of 27 cm<sup>-1</sup> V<sup>-1</sup>.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas2003info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf49-60http://sedici.unlp.edu.ar/handle/10915/121267enginfo:eu-repo/semantics/altIdentifier/issn/0022-0728info:eu-repo/semantics/altIdentifier/doi/10.1016/S0022-0728(03)00050-0info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by/4.0/Creative Commons Attribution 4.0 International (CC BY 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-10-22T17:09:39Zoai:sedici.unlp.edu.ar:10915/121267Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-10-22 17:09:39.834SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
title In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
spellingShingle In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
Bolzán, Agustín Eduardo
Ciencias Exactas
Química
Thiourea
Electro-oxidation
Formamidine disulphide
FTIRRAS
Gold
Electrodissolution
title_short In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
title_full In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
title_fullStr In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
title_full_unstemmed In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
title_sort In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
dc.creator.none.fl_str_mv Bolzán, Agustín Eduardo
Iwasita, T.
Arvia, Alejandro Jorge
author Bolzán, Agustín Eduardo
author_facet Bolzán, Agustín Eduardo
Iwasita, T.
Arvia, Alejandro Jorge
author_role author
author2 Iwasita, T.
Arvia, Alejandro Jorge
author2_role author
author
dc.subject.none.fl_str_mv Ciencias Exactas
Química
Thiourea
Electro-oxidation
Formamidine disulphide
FTIRRAS
Gold
Electrodissolution
topic Ciencias Exactas
Química
Thiourea
Electro-oxidation
Formamidine disulphide
FTIRRAS
Gold
Electrodissolution
dc.description.none.fl_txt_mv The electro-oxidation of gold and thiourea (TU) in aqueous acid solutions is investigated by means of in situ FTIRRAS measurements complemented by voltammetry. The formation of soluble species related to the gold(I)-TU complex and TU electrooxidation products is monitored by following the changes in the IR spectra with the applied potential in the range -0.1 -1.5 V. Experimental data show that gold electrodissolution produces soluble [Au(CS(NH<sub>2</sub>)<sub>2</sub>)<sub>2</sub>]<sub>2</sub>SO<sub>4</sub> species. The IR spectrum of solid samples of this complex is reported. The electrodissolution reaction begins at approximately 0.15 V (SHE), concomitantly with the early stages of TU electro-oxidation. The electro-oxidation of TU on gold in acid solutions produces formamidine disulphide (FDS) at potentials below 1.2 V (SHE). The formation of the gold complex and that of FDS are quasi-reversible processes, as revealed by FTIRRAS data. Once the formation of the oxygen-containing layer on gold sets in, the electro-oxidation of TU and FDS yields carbon dioxide, sulphate ions and CN-containing products. Adsorbed sulphate species, which are also detected from 1.2 V upwards, exhibit a band shift of 27 cm<sup>-1</sup> V<sup>-1</sup>.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas
description The electro-oxidation of gold and thiourea (TU) in aqueous acid solutions is investigated by means of in situ FTIRRAS measurements complemented by voltammetry. The formation of soluble species related to the gold(I)-TU complex and TU electrooxidation products is monitored by following the changes in the IR spectra with the applied potential in the range -0.1 -1.5 V. Experimental data show that gold electrodissolution produces soluble [Au(CS(NH<sub>2</sub>)<sub>2</sub>)<sub>2</sub>]<sub>2</sub>SO<sub>4</sub> species. The IR spectrum of solid samples of this complex is reported. The electrodissolution reaction begins at approximately 0.15 V (SHE), concomitantly with the early stages of TU electro-oxidation. The electro-oxidation of TU on gold in acid solutions produces formamidine disulphide (FDS) at potentials below 1.2 V (SHE). The formation of the gold complex and that of FDS are quasi-reversible processes, as revealed by FTIRRAS data. Once the formation of the oxygen-containing layer on gold sets in, the electro-oxidation of TU and FDS yields carbon dioxide, sulphate ions and CN-containing products. Adsorbed sulphate species, which are also detected from 1.2 V upwards, exhibit a band shift of 27 cm<sup>-1</sup> V<sup>-1</sup>.
publishDate 2003
dc.date.none.fl_str_mv 2003
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/10915/121267
url http://sedici.unlp.edu.ar/handle/10915/121267
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0022-0728
info:eu-repo/semantics/altIdentifier/doi/10.1016/S0022-0728(03)00050-0
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by/4.0/
Creative Commons Attribution 4.0 International (CC BY 4.0)
dc.format.none.fl_str_mv application/pdf
49-60
dc.source.none.fl_str_mv reponame:SEDICI (UNLP)
instname:Universidad Nacional de La Plata
instacron:UNLP
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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score 12.982451

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