现场表面增强红外光谱法研究离子液体/电极界面结构

In-situ Surface-enhanced IR Absorption Spectroscopic Measurements on Electrode/Ionic.Liquid Interface

采用现场表面增强红外光谱法(SEIRAS)对金电极与离子液体1-丁基-3-甲基咪唑三氟甲基磺酸盐([Bmim][OTf])的界面电化学双电层结构进行了研究.循环伏安结果表明离子液体[Bmim][OTf]在金电极上的电化学窗口为4.0 V以上.SEIRAS结果显示阴阳离子在电极表面上发生脱吸附的电位区间以及阳离子和阴离子在电极表面上发生竞争的共吸附,同时阴阳离子在金电极界面上的脱吸附有显著的延迟效应产生,其原因与离子的表面吸附能和马德龙(Madelung)位能综合作用有关.

In-situ surface enhanced infrared absorption spectroscopy is employed to study the interface structure between Au electrode and ionic liquid 1-butyl-3-methylimidazoiium trifluoromethane-sulfonate （[ Bmim] [ （）Tf]）. The electrochemical window of Au/[Bmim][OTf] is about 4.0 V. The IR spectra indicate that the type of ions adsorbed on the electrode surface changes as the potential changes. Competitive adsorption of the cations and the anions occurs on the electrode surface. A significant hysteresis effect during the adsorption/desorption processes of the anions and the cations on the interface has been observed, and it should be ascribed to the results of both the ion Madelung potential and surface adsorption energy.