Image-potential-induced surface states at the Ag(111)-electrolyte interface

Abstract

Image-potential-induced surface states have been detected by electroreflectance spectroscopy at the Ag(111)-aqueous electrolyte interface. A strong optical transition between the occupied “crystal-induced” surface state A and an empty image-potential-induced surface state, both of which occur for Ag(111) at the Λ point of the surface Brillouin zone, is found at h ̵ ω = 3.50 ± 0.05 eV. Assuming an absolute electrode potential of 4.7 eV for the normal hydrogen electrode, a binding energy of 0.4 eV is derived for the ( n = 1) image-potential-induced surface state in 0.5M NaClO 4.