Double layer structure and adsorption/desorption hysteresis of neat ionic liquid on Pt electrode surface - an in-situ IR-visible sum-frequency generation spectroscopic study

The electrochemical interface between a polycrystalline Pt electrode and the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]) has been studied by in-situ IR-visible sum-frequency generation (SFG) spectroscopy. Potential dependent adsorption/desorption processes of OTf anions has been monitored within the electrochemical window. SFG results indicate that the ions form a double layer structure at the interface. Significant adsorption/desorption hysteresis has been observed for the anions on the Pt surface. (c) 2010 Elsevier B.V. All rights reserved.