3-Dimensional Structure of a Prototypical Ionic Liquid–Solid Interface: Ionic Crystal-Like Behavior Induced by Molecule–Substrate Interactions
3-Dimensional Structure of a Prototypical Ionic Liquid–Solid Interface: Ionic Crystal-Like Behavior Induced by Molecule–Substrate Interactions
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DOI：
10.1021/acs.jpcc.6b02232
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发表时间：
2016-05
影响因子：
3.7
通讯作者：
D. Ebeling;Stephan Bradler;B. Roling;A. Schirmeisen
中科院分区：
文献类型：
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作者：
D. Ebeling;Stephan Bradler;B. Roling;A. Schirmeisen
离子液体-电极界面的分子结构最近已经通过原子力显微镜（AFM）方法研究，所述方法聚焦于离子层的垂直结构或最内层的横向结构。在这里，我们结合联合收割机高分辨率原子力显微镜成像与原子力光谱测量，以阐明离子液体硝酸丙铵（PAN）和高度有序的热解石墨（HOPG）之间的界面结构。被吸附分子的最内层的横向结构（即，Stern层）通过振幅调制原子力显微镜（AM-AFM）在分子尺度上分辨。离子液体分子在HOPG表面形成了一个准（4 × 4）R0 °覆盖层。额外的动态模式力谱测量揭示了垂直于表面平面的离子液体的层状结构的存在，并允许精确确定层间距。我们能够推断出三维结构。
The molecular structure of the ionic liquid–electrode interface has been recently investigated by atomic force microscopy (AFM) methods focusing either on the vertical structure of the ion layers or on the lateral structure of the innermost layer. Here, we combine high-resolution AFM imaging with atomic force spectroscopy measurements to elucidate the structure of the interface between the ionic liquid propylammonium nitrate (PAN) and highly ordered pyrolytic graphite (HOPG). The lateral structure of the innermost layer of adsorbed molecules (i.e., the Stern layer) is resolved on the molecular scale by means of amplitude modulation atomic force microscopy (AM-AFM). A quasi (4 × 4)R0° overlayer is formed by the ionic liquid molecules on the HOPG surface. Additional dynamic mode force spectroscopy measurements reveal the existence of a layered structure of the ionic liquid normal to the surface plane and allow for a precise determination of the layer spacing. We are able to infer the three-dimensional struc...