Adsorption of benzoic acid, phthalic acid on gold substrates studied by surface-enhanced Raman scattering spectroscopy and density functional theory calculations
Adsorption of benzoic acid, phthalic acid on gold substrates studied by surface-enhanced Raman scattering spectroscopy and density functional theory calculations
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表面增强拉曼散射光谱和密度泛函理论计算研究苯甲酸、邻苯二甲酸在金基底上的吸附
DOI：
10.1016/j.saa.2012.11.103
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发表时间：
2013-03-01
影响因子：
4.4
通讯作者：
Chen, Xue
中科院分区：
文献类型：
--
作者：
Gao, Jiao;Hu, Yongjun;Chen, Xue
苯甲酸（BA）和邻苯二甲酸（PTA）是结构最简单的芳香羧酸类化合物，可以作为研究芳香羧酸类化合物与金属表面相互作用的典型模型化合物。本工作采用Sers和DFT计算相结合的方法研究了苯甲酸和邻苯二甲酸在金表面的结构和吸附行为。实验结果表明，BA和PTA在Au表面的吸附均为双齿桥结构，即羧酸根通过羧酸根上的两个氧原子与金结合.这两种物质与Au原子形成的复合物的Sers与预测光谱的比较表明，BA以垂直取向而非平面取向吸附在金表面上，而PTA则以微倾斜的方式“站立”在Au表面上，具有两条腿的几何构型，即两个羧酸基团中的所有四个氧原子都在金属表面上相互作用。此外，我们还比较了这两种分子的表面Sers光谱的差异，这可能是一种潜在的分析技术在食品安全领域。皇冠版权所有（C）2012由Elsevier B.V.出版。保留所有权利。
Benzoic acid (BA) and phthalic acid (PTA) are the simplest aromatic carboxylic acids, and they can be regarded as typical model compounds in investigating the interaction of aromatic carboxylic acids with metal surfaces by use of SERS spectroscopy. In this work, we have investigated the structure and adsorption behavior of benzoic acid and phthalic acid on the gold surface with combination of SERS and DFT calculation methods. The experimental results show that both BA and PTA may be adsorbed on the Au surface with a bidentate bridging structure, namely, the carboxylate group(s) being bound to gold via two oxygen atoms in the carboxylate group(s). Comparison of the observed SERS and predicted spectra of the complexes of these two substances with Au atoms indicates that BA is favorable to adsorb on the gold surface with a vertical orientation rather than a flat one, and PTA could "stand up" on the Au surface as a slight tilt with a two-legged geometry, i.e. all four oxygen atoms in two carboxylate groups interact on the metal surface. Apart from that, we compare the discrepancy of SERS spectra between those two molecules, which could be taken as a potential analysis technique in food safety field. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.