School of Chemistry, The University of Nottingham, Nottingham NG7 2RD, UK.
Phys Chem Chem Phys. 2011 Feb 21;13(7):2797-808. doi: 10.1039/c0cp01587c. Epub 2010 Dec 13.
Ionic liquid surfaces can become electrically charged during X-ray photoelectron spectroscopy experiments, due to the flux of photoelectrons leaving the surface. This causes a shift in the measured binding energies of X-ray photoelectron peaks that depends on the magnitude of the surface charging. Consequently, a charge correction method is required for ionic liquids. Here we demonstrate the nature and extent of surface charging in ionic liquids and model it using chronopotentiometry. We report the X-ray photoelectron spectra for a range of imidazolium based ionic liquids and investigate the use of long alkyl chains (C(n)H(2n+1), n ≥ 8) and the imidazolium nitrogen, both of which are part of the ionic liquid chemical structure, as internal references for charge correction. Accurate and reproducible binding energies are obtained which allow comparisons to be made across ionic liquid-based systems.
在 X 射线光电子能谱实验中，由于光电子离开表面的通量，离子液体表面可能会带电。这会导致测量的 X 射线光电子峰的结合能发生偏移，具体取决于表面充电的大小。因此，需要对离子液体进行电荷校正。在这里，我们展示了离子液体表面充电的性质和程度，并使用计时电位法对其进行了建模。我们报告了一系列基于咪唑的离子液体的 X 射线光电子能谱，并研究了长烷基链（C(n)H(2n+1)，n ≥ 8）和咪唑氮的用途，它们都是离子液体化学结构的一部分，作为电荷校正的内部参考。获得了准确且可重复的结合能，从而可以在基于离子液体的系统之间进行比较。
