Metal monolayer deposition by replacement of metal adlayers on electrode surfaces

A new metal deposition method is demonstrated by deposition of a submonolayer of Pt, a monolayer of Pd and a bilayer of Ag on Au(111) surfaces by using a Cu adlayer as a template. The deposition of these metals occurs as a spontaneous irreversible redox process in which a Cu adlayer, obtained by underpotential deposition, is oxidized by more noble metal cations, which are reduced and simultaneously deposited. The Pt deposit is a two-dimensional submonolayer consisting of partially interconnected nano-clusters of monoatomic height. Pd forms a uniform, but textured monolayer, while Ag forms a bilayer. The deposit of each metal uniformly covers the entire gold surface without preferential deposition along the step edges. This method provides surface adlayer-controlled growth, as compared to the current distribution controlled growth in conventional electrodeposition. (C) 2001 Elsevier Science B.V. All rights reserved.