Molecular Dynamics Simulation of Sum Frequency Generation Spectra of Aqueous Sulfuric Acid Solution
Molecular Dynamics Simulation of Sum Frequency Generation Spectra of Aqueous Sulfuric Acid Solution
复制标题
硫酸水溶液和频发生谱的分子动力学模拟
DOI：
10.1021/jp200269k
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
A. Morita
中科院分区：
文献类型：
--
作者：
T. Ishiyama;A. Morita
采用分子动力学（MD）模拟方法研究了浓度为0.02x（x为摩尔分数）的硫酸水溶液的表面结构。该模型被应用于计算SFG光谱的假设，硫酸在表面的酸解离是相同的，在散装。计算的SFG光谱很好地再现了实验，表明酸解离的假设是有效的，在一个相对较低的浓度范围内。在表面区域的组成离子的密度分布示出了不同的表面偏好的水合氢离子阳离子，硫酸氢根阴离子，和硫酸根二价阴离子，从而形成双电层和强烈扰动的表面水的取向结构的顺序。在氢键OH伸缩区的SFG强度的增强和悬空（自由）OH区域的耗尽从界面结构阐明。
The surface structure of aqueous sulfuric acid solution at 0.02x(xis the mole fraction) concentration is investigated by molecular dynamics (MD) simulation with newly developed flexible and polarizable molecular models. The models are applied to calculate the SFG spectrum on the assumption that the acid dissociation of sulfuric acid at the surface is the same as in the bulk. The calculated SFG spectrum well reproduces the experimental one, indicating that the assumption on the acid dissociation is valid in a relatively low concentration range. The density profiles of the constituent ions at the surface region show distinct surface preference in the order of the hydronium cation, bisulfate anion, and sulfate dianion, which thereby forms an electric double layer and strongly perturbs the orientational structure of surface water. The enhancement of the SFG intensity at the hydrogen-bonding OH stretching region and the depletion at the dangling (free) OH region are elucidated from the interfacial structure.