Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions
- Autores
- Bolzán, Agustín Eduardo; Iwasita, T.; Arvia, Alejandro Jorge
- Año de publicación
- 2005
- Idioma
- inglés
- Tipo de recurso
- artículo
- Estado
- versión publicada
- Descripción
- The voltammetric behaviour of tetramethylthiourea (TMTU) dissolved in aqueous perchloric and sulphuric acid solutions on polycrystalline gold combined with in situ Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) was investigated. Conventional and triangular modulated voltammetry and rotating disc electrode data demonstrate the occurrence of two redox surface processes in the potential ranges −0.1 ≤ E ≤ −0.3 V and 0.7 ≤ E ≤ 0.8 V (versus SHE), respectively. These processes would involve the participation of TMTU adsorbates. The redox surface process observed in the range −0.1 to −0.3 V can be related to the electrosorption of TMTU. The absence of infrared absorption bands from these adsorbates agrees with a flat, almost parallel adsorption of TMTU molecules on gold that has been already reported. In the range 0.4 V ≤ E ≤ 0.8 V both electrochemical and spectroscopic data indicate the anodic formation of soluble gold–TMTU complex and tetramethylformamidine disulphide (TMFDS2+) ions presumably via Au(TMTU)+ adsorbates. The kinetics of soluble gold– TMTU complex ion formation is under diffusion control, whereas the formation of TMFDS2+ ions behaves as a rather irreversible process with the anodic slope, derived from current–potential curves, ∂E/∂ log I = 0.120 V decade−1 at 298 K. At E > 1.2 V, the global electro-oxidation of both TMTU and TMFDS2+ species yields carbon dioxide, sulphate ions and carbonyl-containing compounds, as indicated by IR spectra. These reactions involve the participation of oxygen-containing adsorbates produced from water electro-oxidation on gold.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas - Materia
-
Ciencias Exactas
Química
Tetramethylthiourea
Electro-oxidation
FTIRRAS
Gold
Electrodissolution - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- http://creativecommons.org/licenses/by-nc-sa/4.0/
- Repositorio
- Institución
- Universidad Nacional de La Plata
- OAI Identificador
- oai:sedici.unlp.edu.ar:10915/119201
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Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutionsBolzán, Agustín EduardoIwasita, T.Arvia, Alejandro JorgeCiencias ExactasQuímicaTetramethylthioureaElectro-oxidationFTIRRASGoldElectrodissolutionThe voltammetric behaviour of tetramethylthiourea (TMTU) dissolved in aqueous perchloric and sulphuric acid solutions on polycrystalline gold combined with in situ Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) was investigated. Conventional and triangular modulated voltammetry and rotating disc electrode data demonstrate the occurrence of two redox surface processes in the potential ranges −0.1 ≤ E ≤ −0.3 V and 0.7 ≤ E ≤ 0.8 V (versus SHE), respectively. These processes would involve the participation of TMTU adsorbates. The redox surface process observed in the range −0.1 to −0.3 V can be related to the electrosorption of TMTU. The absence of infrared absorption bands from these adsorbates agrees with a flat, almost parallel adsorption of TMTU molecules on gold that has been already reported. In the range 0.4 V ≤ E ≤ 0.8 V both electrochemical and spectroscopic data indicate the anodic formation of soluble gold–TMTU complex and tetramethylformamidine disulphide (TMFDS<sup>2+</sup>) ions presumably via Au(TMTU)<sup>+</sup> adsorbates. The kinetics of soluble gold– TMTU complex ion formation is under diffusion control, whereas the formation of TMFDS2+ ions behaves as a rather irreversible process with the anodic slope, derived from current–potential curves, ∂E/∂ log I = 0.120 V decade−1 at 298 K. At E > 1.2 V, the global electro-oxidation of both TMTU and TMFDS<sup>2+</sup> species yields carbon dioxide, sulphate ions and carbonyl-containing compounds, as indicated by IR spectra. These reactions involve the participation of oxygen-containing adsorbates produced from water electro-oxidation on gold.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas2005info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf1044-1058http://sedici.unlp.edu.ar/handle/10915/119201enginfo:eu-repo/semantics/altIdentifier/url/https://www.sciencedirect.com/science/article/abs/pii/S001346860500592Xinfo:eu-repo/semantics/altIdentifier/issn/0013-4686info:eu-repo/semantics/altIdentifier/doi/10.1016/j.electacta.2005.05.043info: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:UNLP2025-09-29T11:28:05Zoai:sedici.unlp.edu.ar:10915/119201Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:28:05.875SEDICI (UNLP) - Universidad Nacional de La Platafalse |
dc.title.none.fl_str_mv |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions |
title |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions |
spellingShingle |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions Bolzán, Agustín Eduardo Ciencias Exactas Química Tetramethylthiourea Electro-oxidation FTIRRAS Gold Electrodissolution |
title_short |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions |
title_full |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions |
title_fullStr |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions |
title_full_unstemmed |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on gold in aqueous acid solutions |
title_sort |
Combined voltammetry and in situ infrared spectroscopy of tetramethylthiourea on 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 Tetramethylthiourea Electro-oxidation FTIRRAS Gold Electrodissolution |
topic |
Ciencias Exactas Química Tetramethylthiourea Electro-oxidation FTIRRAS Gold Electrodissolution |
dc.description.none.fl_txt_mv |
The voltammetric behaviour of tetramethylthiourea (TMTU) dissolved in aqueous perchloric and sulphuric acid solutions on polycrystalline gold combined with in situ Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) was investigated. Conventional and triangular modulated voltammetry and rotating disc electrode data demonstrate the occurrence of two redox surface processes in the potential ranges −0.1 ≤ E ≤ −0.3 V and 0.7 ≤ E ≤ 0.8 V (versus SHE), respectively. These processes would involve the participation of TMTU adsorbates. The redox surface process observed in the range −0.1 to −0.3 V can be related to the electrosorption of TMTU. The absence of infrared absorption bands from these adsorbates agrees with a flat, almost parallel adsorption of TMTU molecules on gold that has been already reported. In the range 0.4 V ≤ E ≤ 0.8 V both electrochemical and spectroscopic data indicate the anodic formation of soluble gold–TMTU complex and tetramethylformamidine disulphide (TMFDS<sup>2+</sup>) ions presumably via Au(TMTU)<sup>+</sup> adsorbates. The kinetics of soluble gold– TMTU complex ion formation is under diffusion control, whereas the formation of TMFDS2+ ions behaves as a rather irreversible process with the anodic slope, derived from current–potential curves, ∂E/∂ log I = 0.120 V decade−1 at 298 K. At E > 1.2 V, the global electro-oxidation of both TMTU and TMFDS<sup>2+</sup> species yields carbon dioxide, sulphate ions and carbonyl-containing compounds, as indicated by IR spectra. These reactions involve the participation of oxygen-containing adsorbates produced from water electro-oxidation on gold. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas |
description |
The voltammetric behaviour of tetramethylthiourea (TMTU) dissolved in aqueous perchloric and sulphuric acid solutions on polycrystalline gold combined with in situ Fourier transform infrared reflection absorption spectroscopy (FTIRRAS) was investigated. Conventional and triangular modulated voltammetry and rotating disc electrode data demonstrate the occurrence of two redox surface processes in the potential ranges −0.1 ≤ E ≤ −0.3 V and 0.7 ≤ E ≤ 0.8 V (versus SHE), respectively. These processes would involve the participation of TMTU adsorbates. The redox surface process observed in the range −0.1 to −0.3 V can be related to the electrosorption of TMTU. The absence of infrared absorption bands from these adsorbates agrees with a flat, almost parallel adsorption of TMTU molecules on gold that has been already reported. In the range 0.4 V ≤ E ≤ 0.8 V both electrochemical and spectroscopic data indicate the anodic formation of soluble gold–TMTU complex and tetramethylformamidine disulphide (TMFDS<sup>2+</sup>) ions presumably via Au(TMTU)<sup>+</sup> adsorbates. The kinetics of soluble gold– TMTU complex ion formation is under diffusion control, whereas the formation of TMFDS2+ ions behaves as a rather irreversible process with the anodic slope, derived from current–potential curves, ∂E/∂ log I = 0.120 V decade−1 at 298 K. At E > 1.2 V, the global electro-oxidation of both TMTU and TMFDS<sup>2+</sup> species yields carbon dioxide, sulphate ions and carbonyl-containing compounds, as indicated by IR spectra. These reactions involve the participation of oxygen-containing adsorbates produced from water electro-oxidation on gold. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005 |
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 |
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publishedVersion |
dc.identifier.none.fl_str_mv |
http://sedici.unlp.edu.ar/handle/10915/119201 |
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http://sedici.unlp.edu.ar/handle/10915/119201 |
dc.language.none.fl_str_mv |
eng |
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eng |
dc.relation.none.fl_str_mv |
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openAccess |
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http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) |
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