Smoothening Mechanism of Thiourea on Silver Electrodeposition : Real Time Imaging of the Growth Front Evolution
Ag electrodeposits were grown on a polycrystalline Ag cathode at either 0.01 or 1 mA cm<sup>-2</sup> from aqueous 5 × 10<sup>-3</sup> M Ag<sub>2</sub>SO<sub>4</sub> + 10<sup>-2</sup> M H<sub>2</sub>SO<sub>4</sub> + 0...
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| Autores principales: | , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
1999
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/127440 https://pubs.acs.org/doi/abs/10.1021/la9806092 |
| Aporte de: |
| Sumario: | Ag electrodeposits were grown on a polycrystalline Ag cathode at either 0.01 or 1 mA cm<sup>-2</sup> from aqueous 5 × 10<sup>-3</sup> M Ag<sub>2</sub>SO<sub>4</sub> + 10<sup>-2</sup> M H<sub>2</sub>SO<sub>4</sub> + 0.5 M Na<sub>2</sub>SO<sub>4</sub>, in the absence and presence of different amounts of thiourea (TU). The cathode/solution interface evolution in a quasi-bidimensional electrochemical cell was followed with a video microscope imaging system. From TU-free solution a nodular morphology at 0.01 mA cm<sup>-2</sup> and a branched morphology at 1 mA cm<sup>-2</sup> were observed. At 0.01 mA cm<sup>-2</sup> the presence of TU drove the interface motion to a stable roughness regime by suppressing the nucleation and growth of instabilities. Accordingly, the characteristics of the growth front were consistent with the predictions of the Edwards−Wilkinson equation for the interface motion. At 1 mA cm<sup>-2</sup>, those electrodeposits grown in the presence of TU showed a decrease in both the nucleation and growth rates of instabilities, although they were not fully suppressed. |
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