Au(111)电极表面溴离子吸附诱导的表面应力的理论研究

Theoretical Study on Adsorbate-induced Surface Stress of Bromide Monolayer on Au(111) Electrode

以Br-为例,应用格子气模型,建立了阴离子吸附层对Au(111)电极表面应力贡献的统计热力学理论,计算了吸附层Br-间的相互作用能及表面应力的贡献。计算结果表明,总的表面应力是压缩性的;在高覆盖度区域,表面应力与覆盖度近似呈直线关系;在表面吸附层应力的多种物理起源中,通过底物的分子间作用力有着决定性的贡献,揭示了分子的吸附能间接地起着重要作用。

Taking Br^- as an example, the statistical thermodynamic theory of surface stress of anion adsorption monolayer on Au（111） has been established using the lattice gas model. The effective pair interaction energy and the surface stress in Br- adsorption layer at the Au（111） electrode surface have been calculated. The calculated results indicate that the surface stress in Br- adsorption layer at the Au（111） electrode is compressive. At high coverage, the surface stress increased linearly with coverage. Among various components of the adsorbate-adsorbate interaction en- ergies in the adsorption layer, the substrate-mediated interaction is significant for the adsorbate-induced surface stress, which shows that indirect contribution of the adsorption energy of Br^- through the substrate-mediated interaction is very important.