Co-Adsorption of Fluoride and Hydroxide Ions on Ag(111) in Alkaline Electrolytes: Electrochemical and SHG Studies
Научная публикация
| Общее |
Язык:
Английский,
Жанр:
Статья (Full article),
Статус опубликования:
Опубликована,
Оригинальность:
Оригинальная
|
| Журнал |
Zeitschrift fur Physikalische Chemie-International Journal of Research in Physical Chemistry and Chemical Physics
ISSN: 0942-9352
, E-ISSN: 2196-7156
|
| Вых. Данные |
Год: 2003,
Том: 217,
Страницы: 557-572
Страниц
: 16
DOI:
10.1524/zpch.217.5.557.20458
|
| Ключевые слова |
Ag(111), Alkaline Electrolyte, Co-adsorption, Fluoride, Hydroxide, Second Harmonic Generation (SHG), Surface Oxide |
| Авторы |
Danckwerts M.
1
,
Savinova E.R.
1,2,3
,
Horswell S.
1
,
Pettinger B.
1
,
Doblhofer K.
1
|
| Организации |
| 1 |
Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4–6, 14195 Berlin, Germany
|
| 2 |
Boreskov Institute of Catalysis, Russian Academy of Sciences, Pr. Akademika Lavrentieva 5, 630090 Novosibirsk, Russian Federation
|
| 3 |
Technische Universität München, Physik-Department E19, James-Franck-Str. 1, 85748 Garching, Germany
|
|
Информация о финансировании (1)
Hydroxide (OH−) adsorption at Ag(111)/alkaline electrolyte interfaces is the initial step leading to the formation of surface oxide. We investigate how OH− anion adsorption is influenced by co-adsorption of supporting electrolyte anions (F−). Pure NaF and NaOH as well as mixed electrolytes ranging from pH = 5.8 to 14 are investigated. The rotational anisotropy of the second harmonic generation (SHG) signal is measured to distinguish
adsorptive processes from structural changes on the Ag surface. Our results clearly show a cross-over from F−-dominated to OH−-dominated adsorption, while both species remain charged upon adsorption. At more positive potentials, but below the reversible potential of bulk oxide growth, OH is discharged leading to sub-monolayer oxide build-up, whereas in acidic electrolyte, Ag is dissolved. At intermediate pH, the formation of a structured
OH−/F− co-adsorbed layer is proposed.