SNIFTIRS studies of the electrical double layer at gold electrodes

Studies of double layer structure at gold electrodes using subtractively normalized interfacial FTIR spectroscopy are presented. It is shown that, when a hemispherical window is used to introduce the infrared radiation into the electrochemical cell, a significant increase in sensitivity results. Data are presented illustrating the reorientation of solvent dipoles in the double layer. In addition, results obtained for the accumulation of perchlorate and nitrate ions at single crystal gold electrodes are discussed. In the former case, analysis of the integrated intensity of the perchlorate band at 1109 cm(-1) is used to show the potential region over which the surface excess follows the Gouy-Chapman theory and the potential region in which perchlorate ion is specifically adsorbed. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.