X-RAY SURFACE DIFFRACTION OF METAL DEPOSITS AT METAL/LIQUID INTERFACES PART I: COPPER DEPOSIT ON Au(100)

Abstract

In this work the Cu deposition on Au (100) in aqueous perchloric acid has been investigated by in situ X-ray surface diffraction (XRSD). The Cu deposition reaction on gold single crystals exhibits an underpotential deposition (UPD) whereby a fraction of a monolayer is formed. The XRSD measurements show that the Cu UPD layer has a primitive (1×1) structure and that the adsorbed Cu species sit in fourfold hollow sites with a vertical distance between the Cu adlayer and the gold surface of 1.4 Å. The results are discussed in consideration of STM,1 EXAFS2 and XSW3 experiments.