Adsorption of iodide ions on bismuth single crystal planes from solutions in methanol

The adsorption of I- ions on the (111), (001) and (01 (1) over bar) planes of a bismuth single crystal electrode from solutions in methanol has been i nvestigated by means of differential capacity and electrode charge measurem ents. The ionic charge due to the specific adsorption has been obtained usi ng the mixed-electrolyte method. The results have been analyzed and some ch aracteristics calculated by the simple virial adsorption isotherm and class ical inner layer model. It has been found that the difference in the adsorp tion characteristics of I- ions on various planes of the Bi single crystal in methanol is more pronounced than in the case of Cl- and Br- ions. This i s caused by the much stronger adsorption of I- ions on Bi that reduce the i nfluence of the solvent on the adsorption process. The difference in inner layer capacity for various Bi single crystal planes in methanol has been fo und to be lower than that in 2-propanol and close to that in ethanol and wa ter. (C) 1999 Elsevier Science Ltd. All rights reserved.