Deposition of copper and sulfate on Au(111): New insights

作者：Madry B; Wandelt K; Nowicki M^*

来源：Applied Surface Science, 2016, 388: 678-683.

DOI：10.1016/j.apsusc.2016.02.151

• Copper
• Gold
• Sulfate
• Solid-liquid interface
• Surface structure
• Underpotential deposition (UPD)
• Overpotential deposition (OPD)
• Cyclic voltammetry (CV)
• Electrochemical scanning tunneling microscopy (EC-STM)

The adsorption of sulfate anions (SO42-) and copper cations on Au(1 1 1) from CuSO4 containing H2SO4 solution was investigated by cyclic voltammetry (CV) and scanning tunneling microscopy (STM). The underpotential deposition from solution results first in the formation of 2/3 monolayer of copper with the well known (root 3 x root 3) structure of sulfate followed by the completion of the first copper monolayer at lower potentials. Just after formation of 1ML of Cu STM reveals a disordered surface. At more negative potential values, already in the overpotential deposition region, the STM images reflect a (root 3 x root 7) sulfate structure on terraces of the first pseudomorphic Cu layer, a (root 3, root 3)-like structure on terraces of the second uncompleted Cu layer with sulfate anions residing in atomic vacancies, and the known Moire structure on terraces of the multi -layer Cu deposit. The formation of the (root 3 x root 7) sulfate structure on pseudomorphic monolayer Cu terraces on Au(1 1 1) is discussed in the context of results obtained for sulfate on bare Au(1 1 1) and Cu(1 1 1) electrodes in H2SO4 solution.

• 出版日期2016-12-1