Ionic liquid ultrathin films at the surface of Cu(100) and Au(111)
Ionic liquid ultrathin films at the surface of Cu(100) and Au(111)
复制标题
DOI：
10.1063/1.4975101
复制
发表时间：
2017-02-07
影响因子：
4.4
通讯作者：
Rangan, Sylvie
中科院分区：
文献类型：
--
作者：
Biedron, Aleksandra B.;Garfunkel, Eric L.;Rangan, Sylvie
用物理气相沉积法在Au（111）和Cu（100）表面制备了离子液体（IL）1-甲基-3-辛基咪唑双（三氟甲基磺酰基）酰胺的单层到多层膜。使用扫描隧道显微镜的组合，以及紫外和X射线光电子能谱的离子表面相互作用进行了研究。结果表明，IL在金属表面不分解，IL与Cu（100）表面的相互作用远强于与Au（111）表面的相互作用。因此，在室温下的STM成像导致在Cu（100）上的单层覆盖比在Au（111）上的单层覆盖更稳定的成像，并且功函数测量指示在Cu上沉积IL单层时的大的界面偶极子。额外的IL沉积在两个表面上的IL核心水平的结果在两个不同的行为：一个渐进的能量转移的核心水平上的Au和一组两个明确定义的单层和多层的核心水平组件在固定的能量上发现，由于形成一个紧密结合的单层。最后，提出特别强的阳离子-Cu相互作用导致阴离子的稳定化，并防止其在Cu（100）表面分解。出版社：AIP Publishing
Monolayer to multilayer ultrathin films of the ionic liquid (IL) 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl) amide have been prepared on Au(111) and Cu(100) surfaces using physical vapor deposition. The ion-surface interactions are studied using a combination of scanning tunnel microscopy, as well as ultraviolet and x-ray photoemission spectroscopies. It is found that the IL does not decompose at the surface of the metals, and that the IL interaction with the Cu(100) surface is much stronger than with the Au(111) surface. As a consequence, STM imaging at room temperature results in more stable imaging at the monolayer coverage on Cu(100) than on Au(111), and work function measurements indicate a large interface dipole upon deposition of a monolayer of IL on Cu. Additional IL depositions on the two surfaces result in two distinct behaviors for the IL core levels: a gradual energy shift of the core levels on Au and a set of two well defined monolayer and multilayer core level components found at fixed energies on Cu, due to the formation of a tightly bound monolayer. Finally, it is proposed that the particularly strong cation-Cu interaction leads to stabilization of the anion and prevents its decomposition at the surface of Cu(100). Published by AIP Publishing.