Pt(100)/离子液体OMIPF6界面结构的STM研究

本文运用电化学扫描隧道显微术研究了离子液体OMIPF₆中Pt（100）表面结构在电化学双层区随电极电位的变化. OMI⁺阳离子在Pt（100）表面形成有序吸附结构，并且在约1.2 V宽的电位区间内稳定地存在Pt（100）表面。在电位负于-0.6 V时，有序吸附结构会发生向无序吸附结构的转变. 在电位正于+0.6 V时，较强的静电排斥力才能克服OMIPF₆与Pt（100）表面之间的化学作用，从而导致OMI+阳离子的脱附. 研究表明，OMI+阳离子具有的较长烷基侧链与Pt金属产生的较强化学相互作用是影响该Pt（100）/ OMIPF6界面结构的重要因素.

An STM study on the Structure of Pt(100)/Ionic Liquid OMIPF6 Interface

Potential-dependent structures of Pt(100)/ionic liquid 1-methyl-3-octylimidazolium hexafluorophosphate (OMIPF₆) interface have been studied by electrochemical scanning tunneling microscopy (ECSTM). The cation OMI⁺ forms ordered structure on Pt(100) surface, which exists in a potential region of about 1.2 V. When the potential is more negative than -0.6 V, it can be seen that the ordered structure transforms to disordered structure. When the potential shifts positively to +0.6 V, the desorption of cations OMI⁺ occurs, which indicates that strong electrostatic repulsion is needed to overcome chemical interaction between OMIPF6 and Pt(100) surface, leading to the desorption. The above results demonstrate that owing to the longer alkyl chain OMI+ can interact strongly with Pt(100), which plays an important role in the structure of Pt(100)/ OMIPF₆ interface.