The three low index Au single crystal surfaces are known to reconstruct in an electrochemical cell. An understanding of the influence of reconstruction on the adsorption of cations and anions is very important to many areas of electrochemistry. I have applied both ex situ low energy electron diffraction (LEED) and in situ surface X-ray scattering (SXS) techniques in addition to traditional electrochemistry to study reconstruction of the Au surfaces in the presence of anions (Cl-,Br-) and small organic molecules (pyridine, bipyridine). I also used in situ EXAFS to study the coadsorption of Cu and anions (SO42-, Cl- Br-) at the Au/electrolyte interface.
LEED experiments have shown that the adsorption of Br- on Au(100) lifts the surface reconstruction at a small coverage . Very interesting structure have been observed for the Br- overlayer formed at this surface of gold.
Potential induced structural transformation (1x1)(1x23) between the unreconstructed (1x1) and the reconstructed (1x23) surfaces of Au(111) electrode in the presence of organic molecules was studied in situ using surface x-ray scattering (SXS) technique. It was shown that adsorption of small organic molecules such as pyridine and bipyridine inhibits this structural transformation. No direct correlation between the surface coverage and lifting of the reconstruction was observed.