SERS detection of the vibrational stark effect from nitrile-terminated SAMs to probe electric fields in the diffuse double-layer
SERS detection of the vibrational stark effect from nitrile-terminated SAMs to probe electric fields in the diffuse double-layer
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DOI：
10.1021/ja017656s
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发表时间：
2002-03-20
影响因子：
15
通讯作者：
Harris, JM
中科院分区：
文献类型：
--
作者：
Oklejas, V;Sjostrom, C;Harris, JM
在表面增强拉曼散射光谱中观察到的振动斯塔克效应与侧基腈功能化的自组装单分子膜。斯塔克调谐的腈伸缩频率作为一个本地化的探针的电场在扩散双电层的SAM改性的电化学界面。在低离子强度下的斯塔克调谐速率对应于双层中的局部电场（E）的合理值。腈伸缩频率收敛于其各向同性值在接近PZC的施加电位，这表明斯塔克调谐的频率是一个直接探头的E场在界面处。在高离子强度的局部电场的损失表明，探针响应于双层的德拜长度的变化。结果表明，该电场探头的适用性，用于表征扩散双层区域。
The vibrational Stark effect is observed in the surface-enhanced Raman scattering spectra of self-assembled monolayers functionalized with pendant nitrile groups. Stark tuning of the nitrile-stretching frequency serves as a localized probe of the electric field in the diffuse double layer of a SAM-modified electrochemical interface. Stark-tuning rates at low ionic strength correspond to reasonable values of the local electric (E) field in the double layer. The nitrile-stretching frequency converges on its isotropic value at applied potentials approaching the PZC, which indicates that Stark-tuning of the frequency is a direct probe of the E field at the interface. Loss of the local electric field at high ionic strengths shows that the probe responds to changes in the Debye length of the double layer. The results demonstrate the applicability of this electric-field probe for characterizing the diffuse double-layer region.