Comparative Study of the Underpotential Deposition of Bi in an Aqueous Electrolyte and an Ionic Liquid

Abstract

The underpotential deposition (UPD) of Bi on the Au(111) electrode in a 1 M HClO 4 solution and 1-butyl-3-methylimidazolium tetrafluoroborate was investigated using visible-light reflectance measurement and surface X-ray scattering techniques. The electrosorption valency of the UPD reaction of Bi was elucidated, and in a 1 M HClO 4 solution and 1-butyl-3-methylimidazolium tetrafluoroborate, the electrosorption valency was smaller than 3, but the detailed process in the UPD reaction differed in the two electrolytes. The difference could have originated from the difference in the solvation status of Bi 3+ in the two electrolytes rather than from the electrical double-layer structure.