Electrochemical SERS observation of molecular adsorbates on Ru/Pt-modified Au(111) surfaces using sphere-plane type gap-mode plasmon excitation
Electrochemical SERS observation of molecular adsorbates on Ru/Pt-modified Au(111) surfaces using sphere-plane type gap-mode plasmon excitation
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DOI：
10.1016/j.jelechem.2016.11.046
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发表时间：
2017-09-01
影响因子：
4.5
通讯作者：
Uosaki, Kohei
中科院分区：
文献类型：
--
作者：
Ikeda, Katsuyoshi;Kimura, Aya;Uosaki, Kohei
原位电化学表面增强拉曼光谱（Sers）观察了在有表面粗糙度和无表面粗糙度的Au基底上形成的Ru/Pt合金覆盖层。当覆盖层上形成的电化学粗糙的Au基板具有Sers活性，分子吸附物的光谱特征显着影响的表面的结构和组成的不均匀性，导致在电化学条件下的光谱再现性低。另一方面，当在原子限定的Au（111）上形成覆盖层时，在SERS活性球-平面型纳米间隙结构的辅助下获得了高度可再现的Sers光谱。电化学电势的应用明显地诱导光谱变化，例如内部分子振动的电化学斯塔克位移或分子到金属的电荷转移诱导的拉曼带的出现。在Sers观测中使用定义明确的界面，使我们能够获得在金属分子界面的电子振动耦合的信息，以及分子吸附几何的振动信息。(C)© 2016 Elsevier B. V.版权所有。
In-situ electrochemical SERS observation was conducted at Ru/Pt alloyed overlayers formed on Au substrates with and without surface roughness. When the overlayer was formed on an electrochemically roughened Au substrate having SERS activity, spectral features of molecular adsorbates were significantly influenced by structural and compositional inhomogeneity of the surface, resulting in low spectral reproducibility under electrochemical conditions. On the other hand, when the overlayer was formed on an atomically defined Au(111), highly reproducible SERS spectra were obtained with the assistance of SERS-active sphere-plane type nano-gap structures. Application of electrochemical potentials clearly induced spectral variations such as electrochemical Stark shift of the internal molecular vibrations or appearance of molecule-to-metal charge transfer-induced Raman bands. The use of well-defined interfaces in SERS observation enabled us to obtain information on electron-vibration coupling at metal-molecule interfaces as well as vibrational information on molecular adsorption geometry. (C) 2016 Elsevier B.V. All rights reserved.