Park Inhee, Baltruschat H
Institut für physikalische und Theoretische Chemie, Universität Bonn, Römerstraße 164, D-53117, Bonn, Germany.
Institut für physikalische und Theoretische Chemie, Universität Bonn, Römerstraße 164, 53117, Bonn, Germany.
Chemphyschem. 2021 May 17;22(10):952-959. doi: 10.1002/cphc.202100130. Epub 2021 May 4.
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 structure ( on Au(111) prior to Ag underpotential deposition (UPD) and structure ( ) 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.
在含银的硫酸溶液中，利用横向力显微镜（LFM）研究了银在Au(111)上的电沉积过程。摩擦力图像显示，在银欠电位沉积（UPD）之前，吸附的硫酸盐在Au(111)上形成结构（ ），而在完整的单层或双层银上形成结构（ ）。摩擦力随法向载荷的变化呈现出非单调依赖性，这是由于探针进入硫酸盐吸附层的深度增加所致。此外，摩擦力还受到表面银原子覆盖度和迁移率变化的影响。在银覆盖度达到临界值之前，沉积的银原子可能具有足够的迁移率，能够被原子力显微镜（AFM）探针的移动拖动。讨论了在非常高的载荷下探针可能穿透欠电位沉积层的情况，将其作为自修复磨损的一种模型。然而，当银的覆盖度接近1时，沉积的银原子紧密到足以抵抗AFM探针的影响，此时探针仅穿透硫酸盐吸附层。
