Influence of the electric potential on the structure of pyridine adlayers on Au(111) terraces from in-situ scanning tunnelling microscopy imaging
The adsorption and desorption of pyridine (Py) adlayers prepared on Au(111) terraces were studied by in-situ scanning tunnelling microscopy (STM) and conventional voltammetry using an aqueous 0.1 M HClO<sub>4</sub>+10<sup>−4</sup> M Py solution at 298 K. The applied potential...
| Authors: | , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 1999 |
| Country: | Argentina |
| Institution: | Universidad Nacional de La Plata |
| Repository: | SEDICI (UNLP) |
| Language: | English |
| OAI Identifier: | oai:sedici.unlp.edu.ar:10915/118286 |
| Online Access: | http://sedici.unlp.edu.ar/handle/10915/118286 |
| Access Level: | Open access |
| Keyword: | Ciencias Exactas Química Scanning tunnelling microscopy Electric potential Pyridine adlayers Au(111) terraces |
| Summary: | The adsorption and desorption of pyridine (Py) adlayers prepared on Au(111) terraces were studied by in-situ scanning tunnelling microscopy (STM) and conventional voltammetry using an aqueous 0.1 M HClO<sub>4</sub>+10<sup>−4</sup> M Py solution at 298 K. The applied potential covered the range 0.15 V < E < 1.2 V (vs. SHE), i.e. potentials above and below E<sub>pzc</sub>, the potential of zero charge of Au(111). In the range E<sub>pzc</sub> < E < 0.96 V, hexagonal (4×4) ordered domains corresponding to Py molecules adsorbed vertically on the Au(111) surface coexist with disordered adlayer domains, but for E < E<sub>pzc</sub>, the ordered adlayer structure disappears leaving uncovered Au(111) domains. Similarly, for E > 0.96 V, the (4×4) adlayer lattice is removed completely leading to a bare Au(111) surface. By stepping E backwards to a value in the range E<sub>pzc</sub> < E < 0.96 V, the readsorption of Py takes place and the (4×4) adlayer domains are recovered in a few minutes. STM data offer the possibility of discussing anion adsorption and the early electroformation stages of the OH-containing adlayer on Au(111) terraces. |
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