In-situ ATR-IR study of water on gold electrode surface

Three distinct water species were detected on gold (Au) film electrodes deposited on Si prism in 1 mM KX (X = F, Cl, Br or I) solutions using highly sensitive attenuated total reflection (ATR)-IR spectroscopy. Water molecules associated with halide ions at the Au surface give a fairly high frequency for O-H stretching mode at ca. 3585 cm(-1) with an extremely narrow band width of 50 cm(-1), corresponding to fairly weak hydrogen bonding. This band frequency depends not on the halide species but on the alkali metal cations. Furthermore, it was found that the IR background intensity is approximately proportional to the surface coverage of Br(-). (C) 1999 Elsevier Science B.V. All rights reserved.