Adsorption of 1,4-benzenedithiol on gold and silver surfaces: Surface-enhanced Raman scattering study
Adsorption of 1,4-benzenedithiol on gold and silver surfaces: Surface-enhanced Raman scattering study
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DOI：
10.1006/jcis.2001.7692
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发表时间：
2001-08-15
影响因子：
9.9
通讯作者：
Kim, K
中科院分区：
文献类型：
--
作者：
Joo, SW;Han, SW;Kim, K
利用表面增强拉曼散射（Sers）技术研究了1，4-苯二硫醇（1，4-BDT）在胶体金和银表面的吸附行为。1，4-BDT在金和银表面上分别以单硫醇盐和二硫醇盐的形式解离吸附。无论1，4-BDT的体相浓度如何，在银表面上均形成两个Ag-S键，形成一个具有平面取向的单层膜。在金表面上，单硫醇盐物种，1，4-BDT-1，似乎在非常低的表面覆盖率下呈现相当平坦的取向，但随着表面覆盖率的增加，吸附物呈现垂直取向。此外，当1，4-BDT的体相浓度接近单层覆盖极限时，在金溶胶Sers光谱中出现了一个与S-S伸缩振动相似的536 cm（-1）峰。一个单独的椭圆偏振测量进行真空蒸发的金基板显示，高达tetralayers可以组装在金在1 mM的正己烷溶液中的1，4-BDT，而在最好的双层形成在甲醇或乙醇溶液。1，4-BDT在金和银上的不同吸附质结构总体上与对二甲苯-α，α ′-二硫醇相当。(C)北京：科学出版社.
The adsorption behavior of 1,4-benzenedithiol (1,4-BDT) on colloidal gold and silver surfaces has been investigated by means of surface-enhanced Raman scattering (SERS). 1,4-BDT chemisorbed dissociatively on both gold and silver surfaces but as mono- and dithiolate, respectively. Regardless of the bulk concentration of 1,4-BDT, only a monolayer was assembled on the silver surface with a flat orientation by forming two Ag-S bonds. On the gold surface, the monothiolate species, 1,4-BDT-1, appeared to assume a rather flat orientation at a very low surface coverage, but as the surface coverage was increased, the adsorbate took a perpendicular orientation. Furthermore, when the bulk concentration of 1,4-BDT was close to that required for a full-monolayer coverage limit, a band assignable to the S-S stretching vibration appeared at similar to 536 cm(-1) in the gold sol SERS spectra. A separate ellipsometry measurement performed with vacuum-evaporated gold substrates revealed that up to tetralayers could be assembled on gold in 1 mM n-hexane solution of 1,4-BDT while at best a bilayer formed in either methanol or ethanol solution. The different adsorbate structure of 1,4-BDT on gold and silver was overall quite comparable to that of p-xylene-alpha,alpha ' -dithiol. (C) 2001 Academic Press.