On the electrochemical behavior of formamidine disulfide on gold electrodes in acid media
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http://hdl.handle.net/10045/52738
Títol: | On the electrochemical behavior of formamidine disulfide on gold electrodes in acid media |
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Autors: | Cheuquepán, William | Orts, José M. | Rodes, Antonio |
Grups d'investigació o GITE: | Grupo de Espectroelectroquímica y Modelización (GEM) |
Centre, Departament o Servei: | Universidad de Alicante. Departamento de Química Física | Universidad de Alicante. Instituto Universitario de Electroquímica |
Paraules clau: | Formamidine disulfide | Thiourea | Thioureate | Gold electrodes | Infrared spectroscopy | DFT |
Àrees de coneixement: | Química Física |
Data de publicació: | 1-de març-2016 |
Editor: | Elsevier |
Citació bibliogràfica: | Journal of Electroanalytical Chemistry. 2016, 764: 79-87. doi:10.1016/j.jelechem.2016.01.002 |
Resum: | The adsorption and reactivity of formamidine disulfide (FDS) were studied at gold single crystal and thin film electrodes in perchloric acid solutions and the results of cyclic voltammetry and in situ infrared spectroscopy (SNIFTIR and ATR-SEIRAS) experiments compared with those previously obtained with thiourea (TU). In addition, optimized geometries and theoretical harmonic vibrational frequencies were obtained for adsorbed FDS, TU and thioureate from plane-wave DFT calculations using periodic surface models. These results were compared in the case of TU and thioureate to those previously obtained with a model Au cluster surface with (111) orientation. In the case of FDS, weak adsorption takes place with the S–S bond essentially parallel to the metal surface. No specific bands for adsorbed FDS can be identified in the experimental ATR-SEIRA spectra. These latter spectra suggest that adsorbed thioureate species are spontaneously formed upon dissociative adsorption of FDS when dosing this molecule at open circuit. Some of the adsorbed thioureate species undergo reductive protonation giving rise to a mixed adlayer formed by adsorbed thioureate and thiourea in a surface process which is faster when a controlled potential of 0.70 V is applied. In agreement with the observations reported when dosing TU, the ratio between TU and thioureate adsorbates is found to depend on the electrode potential, being higher for potentials close to the hydrogen evolution limit and decreasing for higher potential values. |
Patrocinadors: | The authors acknowledge the finance by Ministerio de Economía y Competitividad (project CTQ2013-44083-P) and the University of Alicante. William Cheuquepán is grateful for the award of a F.P.I. grant associated to project CTQ2009-13142. |
URI: | http://hdl.handle.net/10045/52738 |
ISSN: | 1572-6657 (Print) | 1873-2569 (Online) |
DOI: | 10.1016/j.jelechem.2016.01.002 |
Idioma: | eng |
Tipus: | info:eu-repo/semantics/article |
Drets: | © 2016 Elsevier B.V. |
Revisió científica: | si |
Versió de l'editor: | http://dx.doi.org/10.1016/j.jelechem.2016.01.002 |
Apareix a la col·lecció: | INV - GEM - Artículos de Revistas |
Arxius per aquest ítem:
Arxiu | Descripció | Tamany | Format | |
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2016_Cheuquepan_etal_JElectrChem_final.pdf | Versión final (acceso restringido) | 1,86 MB | Adobe PDF | Obrir Sol·licitar una còpia |
2016_Cheuquepan_etal_JElectrChem_accepted.pdf | Accepted Manuscript (acceso abierto) | 1,06 MB | Adobe PDF | Obrir Vista prèvia |
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