부산대학교 도서관

In situphotoemission and near-edge X-ray absorption fine structure (NEXAFS) techniques have been used to study the interaction of CO2with an ionic liquid thin film. A thin film of the superbasic ionic liquid (SBIL) trihexyltetradecylphosphonium benzimidazolide ([P66614][benzim]) was prepared on a rutile TiO2(110) surface and exposed to CO2at near-ambient pressures. NEXAFS measurements combined with density functional theory calculations indicate a realignment of [benzim]−anions from 27° from the surface normal to 54° upon exposure to CO2. Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) shows evidence of irreversible CO2absorption in thin films of [P66614][benzim] and a greater concentration of CO2-reacted anions in the deeper layers. These results give a new perspective on CO2uptake in ionic liquids and fundamental interactions at the liquid–gas interface. Understanding this interfacial behavior is important for developing ILs for gas capture applications and may influence the performance of other IL-based technologies.