Vieira Luciana, Schennach Robert, Gollas Bernhard
CEST Competence Centre for Electrochemical Surface Technology GmbH, Viktor-Kaplan-Strasse 2, 2700 Wiener Neustadt, Austria.
Phys Chem Chem Phys. 2015 May 21;17(19):12870-80. doi: 10.1039/c5cp00070j.
The interface of a 1 : 2 molar choline chloride/ethylene glycol deep eutectic solvent with a glassy carbon electrode has been investigated by polarization modulation reflection-absorption spectroscopy (PM-IRRAS). Temporal spectral changes at open circuit potential show the experiments to be surface sensitive and indicate slow adsorption of electrolyte molecules on the electrode surface. In situ spectroelectrochemical PM-IRRAS measurements reveal characteristic potential-dependent changes of band intensities and wavenumber-shifts in the surface spectra. The potential dependent spectral changes are discussed in terms of adsorption, reduction, desorption and reorientation of choline cations at the interface. Analogies are drawn to the ionic layer structure proposed for the architecture of electrode/ionic liquid interfaces. The results show that in situ PM-IRRAS is generally applicable to glassy carbon electrodes and to electrode interfaces with deep eutectic solvents.
采用偏振调制反射吸收光谱法（PM - IRRAS）研究了摩尔比为1∶2的氯化胆碱/乙二醇低共熔溶剂与玻碳电极的界面。开路电位下的时间光谱变化表明该实验对表面敏感，并表明电解质分子在电极表面的吸附缓慢。原位光谱电化学PM - IRRAS测量揭示了表面光谱中带强度和波数位移的特征电位依赖性变化。根据胆碱阳离子在界面处的吸附、还原、解吸和重新取向讨论了电位依赖性光谱变化。与为电极/离子液体界面结构提出的离子层结构进行了类比。结果表明，原位PM - IRRAS通常适用于玻碳电极以及与低共熔溶剂的电极界面。
