Underpotential anion influence

Copper electrodeposition on Au(111) Copper is an interesting metal and has been widely investigated in electrodeposition studies from aqueous solutions. There are numerous publications in the literature on this topic. Furthermore, technical processes to produce Cu interconnects on microchips have been established in aqueous solutions. In general, the quality of the deposits is strongly influenced by the bath composition. On the nanometer scale, one finds different superstmctures in the underpotential deposition regime if different counter-ions are used in the solutions. A co-adsorption between the metal atoms and the anions has been reported. In the underpotential regime, before the bulk deposition begins, one Cu mono-layer forms on Au(lll) [66]. 

As found in preceding sections, the underpotential deposition process is strongly influenced by anion adsorption, or controlled sometimes by the presence of the adsorbed anions. Anion-specific adsorption/desorption seems to take place as an electron transfer process and may be accompanied by the underpotential deposition formation/removal process. ... 

The effect of acetate, citrate, and thiourea on Pb underpotential deposition on Ag(lll) has been studied. The effects of the anionic character of the additives were discussed in relation to changes in voltammograms. The two-dimensional phase transformation was also discussed. The influence of various additives such as dimethylfluoride (DMF) and pyridine on cyclic voltammograms of Cu underpotential deposition on Pt(lll) was observed. Cu underpotential deposition on Pt(lll) was studied in the presence of crystal violet, coumarin, and hydroquinone. ... 

Many ordered surface phases were found on electrodes by electrolytic metal deposition at underpotentials, often having different stractures than those observed by deposition from the gas phase. The reason is that the interactions of the substrate and the deposits with components of the electrolyte influence the forces of interaction between deposited atoms. This is demonstrated particularly well by the influence of anion adsorption on the potential and structure of underpotentially deposited metals. The stracture of the full monolayer is in some cases different from the bulk phase of the deposited metal. The monolayer stracture can be controlled by the stracture of the substrate, and such differences can extend even to the second layer. Three-dimensional nucleation, however, seems to play a minor role in the growth of the bulk phase on foreign substrates when imderpotential deposition takes place. ... 

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