Department of Physical Chemistry, School of Chemistry, University of Nottingham, Nottingham, NG7 2RD.
Phys Chem Chem Phys. 2012 May 7;14(17):6054-66. doi: 10.1039/c2cp23901a. Epub 2012 Mar 22.
Ultraviolet photoelectron spectroscopy (UPS), work function measurements, low energy electron diffraction (LEED) and scanning tunnelling microscopy (STM) have been used to study the adsorption and desorption of 1-ethyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide, [C(2)C(1)Im][Tf(2)N], on the (1×2) clean surface reconstruction of Au(110) in the temperature range 100-674 K. The ionic liquid adsorbed without decomposition, and desorbed without leaving any residue on the surface. For adsorption at room temperature a monolayer of strongly bound ionic liquid was formed with four interface states visible in UP spectra. STM at 100 K showed that the monolayer consisted of well-ordered rows of adsorbed ionic liquid aligned parallel to the close packed rows of surface gold atoms (the [110] direction) with a separation of ×2 (the same as the clean surface reconstruction) between the rows in the orthogonal [001] direction. Multilayer adsorption at room temperature occurred by droplet formation followed by smoothing of the droplets to a layered morphology with time. Heating caused multilayer desorption at temperatures in the 363-383 K range, followed by partial monolayer desorption at 548 K to produce a Au(110)-(1×3) reconstructed surface with sub-monolayer domains of ionic liquid. Desorption of the remaining ionic liquid at 600 K caused the gold surface to reconstruct back to the clean (1×2) reconstruction.
紫外光电子能谱 (UPS)、功函数测量、低能电子衍射 (LEED) 和扫描隧道显微镜 (STM) 已被用于研究 1-乙基-3-甲基咪唑双[(三氟甲基)磺酰]亚胺，[C(2)C(1)Im][Tf(2)N]，在 100-674 K 温度范围内在 Au(110)清洁表面重构 (1×2) 上的吸附和解吸。离子液体吸附而不分解，解吸后表面不留任何残留物。在室温下吸附形成了一层具有四个界面态的强结合离子液体单层，在 UP 光谱中可见。100 K 的 STM 表明，单层由排列成平行于表面金原子密排行（[110]方向）的吸附离子液体的有序行组成，在沿 [001] 方向的正交方向上各行之间的间距为×2（与清洁表面重构相同）。室温下的多层吸附通过液滴形成发生，然后随着时间的推移液滴平滑化为分层形貌。加热导致在 363-383 K 范围内的多层解吸，随后在 548 K 时部分单层解吸产生具有亚单层离子液体域的 Au(110)-(1×3)重构表面。在 600 K 下解吸剩余的离子液体导致金表面重构回清洁的 (1×2) 重构。
