Voltammetric and Surface Conductance Study of the Deposition and Stripping of Mercury on Gold
The voltammetric and surface conductance (SC) responses of thin gold film electrodes during the deposition and stripping of mercury in 0.1 M HC104 solutions have been measured for (i) the potential region corresponding to the underpotential deposition (upd) and stripping (ups), (ii) the formation an...
Guardado en:
| Publicado: |
1990
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_07437463_v6_n4_p839_Romeo http://hdl.handle.net/20.500.12110/paper_07437463_v6_n4_p839_Romeo |
| Aporte de: |
| Sumario: | The voltammetric and surface conductance (SC) responses of thin gold film electrodes during the deposition and stripping of mercury in 0.1 M HC104 solutions have been measured for (i) the potential region corresponding to the underpotential deposition (upd) and stripping (ups), (ii) the formation and stripping of the Hg-Au bulk alloy, and (iii) the deposition and stripping of bulk Hg(0). The analysis of the experimental results shows that the upd mercury grows by an island mechanism up to ὓ 0.7. Linde's surface rule suggests the formation of an interstitial surface phase in this coverage range. The formation of bulk Hg-Au alloy occurs when ὓ = 1 but in the absence of bulk Hg(0). During the stripping of the alloy, the SC is only sensitive to the surface concentration of the Hg(upd) species. Only a relatively small amount of alloy is stripped off during the stripping cycle. It has been verified that the penetration of the mercury atoms into the bulk depends on the grain boundaries concentration. The changes in SC during the formation of bulk Hg(0) indicate that it is a more dense surface phase than the Hg(upd) surface phase. © 1990, American Chemical Society. All rights reserved. |
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