In situ friction study of Ag Underpotential deposition (UPD) on Au(111) in aqueous electrolyte.
Chemphyschem
; 22(10): 952-959, 2021 May 17.
Article
en En
| MEDLINE
| ID: mdl-33734530
ABSTRACT
The electrodeposition of silver on Au(111) was investigated using lateral force microscopy (LFM) in Ag+ containing sulfuric acid. Friction force images show that adsorbed sulfate forms 3 × 7 R 19 . 1 ∘ structure ( θ s u l f a t e = 0 . 2 ) on Au(111) prior to Ag underpotential deposition (UPD) and ( 3 × 3 R 30 ∘ ) structure ( θ s u l f a t e = 0 . 33 ) on a complete monolayer or bilayer of Ag. Variation of friction with normal load shows a non-monotonous dependence, which is caused by increasing penetration of the tip into the sulfate adlayer. In addition, the friction force is influenced by the varying coverage and mobility of Ag atoms on the surface. Before Ag coverage reaches the critical value, the deposited silver atoms may be mobile enough to be dragged by the movement of AFM tip. Possible penetration of the tip into the UPD layer at very high loads is discussed as a model for self-healing wear. However, when the coverage of Ag is close to 1, the deposited Ag atoms are tight enough to resist the influence of the AFM tip and the tip penetrates only into the sulfate adlayer.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Chemphyschem
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2021
Tipo del documento:
Article
País de afiliación:
Alemania