In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions
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...
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2003
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/121267 |
| Aporte de: |
| id |
I19-R120-10915-121267 |
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| record_format |
dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Inglés |
| topic |
Ciencias Exactas Química Thiourea Electro-oxidation Formamidine disulphide FTIRRAS Gold Electrodissolution |
| spellingShingle |
Ciencias Exactas Química Thiourea Electro-oxidation Formamidine disulphide FTIRRAS Gold Electrodissolution Bolzán, Agustín Eduardo Iwasita, T. Arvia, Alejandro Jorge In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions |
| topic_facet |
Ciencias Exactas Química Thiourea Electro-oxidation Formamidine disulphide FTIRRAS Gold Electrodissolution |
| 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>. |
| format |
Articulo Articulo |
| author |
Bolzán, Agustín Eduardo Iwasita, T. Arvia, Alejandro Jorge |
| author_facet |
Bolzán, Agustín Eduardo Iwasita, T. Arvia, Alejandro Jorge |
| author_sort |
Bolzán, Agustín Eduardo |
| title |
In situ FTIRRAS study of the electro-oxidation reactions of thiourea and gold in aqueous acid solutions |
| 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 |
| publishDate |
2003 |
| url |
http://sedici.unlp.edu.ar/handle/10915/121267 |
| work_keys_str_mv |
AT bolzanagustineduardo insituftirrasstudyoftheelectrooxidationreactionsofthioureaandgoldinaqueousacidsolutions AT iwasitat insituftirrasstudyoftheelectrooxidationreactionsofthioureaandgoldinaqueousacidsolutions AT arviaalejandrojorge insituftirrasstudyoftheelectrooxidationreactionsofthioureaandgoldinaqueousacidsolutions |
| bdutipo_str |
Repositorios |
| _version_ |
1764820449087193089 |