Surface-enhanced Raman scattering spectra of thiourea adsorbed at an iron electrode in NaClO4 solution
Surface-enhanced Raman scattering spectra of thiourea adsorbed at an iron electrode in NaClO4 solution
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DOI：
10.1021/jp0257395
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发表时间：
2002-10-03
影响因子：
3.3
通讯作者：
Tian, ZQ
中科院分区：
文献类型：
--
作者：
Cao, PG;Yao, JL;Tian, ZQ
研究了电化学活化铁电极上硫脲的表面增强拉曼散射 (SERS) 光谱与外加电位的函数关系。通过将SERS与硫脲的正常拉曼光谱进行比较，可以清楚地观察到并解释硫脲通过硫原子与轮胎铁表面的配位，CS拉伸的显着下移和NCN对称拉伸的上移。低频模式的出现在大约。分配给 Fe-S 振动的 283 cm(-1) 支持硫脲 S 配位的假设。由于观察到 SCNN 面外弯曲带，硫脲分子的取向被认为以中间角度稍微倾斜于铁表面。 SERS 光谱的电势依赖性表明，硫脲在相对正电势下可能与铁表面相互作用更强烈。 SERS 光谱也证实了支持电解质阴离子 ClO4- 与硫脲的共吸附。
Surface-enhanced Raman scattering (SERS) spectra of thiourea at an electrochemically activated iron electrode have been investigated as a function of applied potential. The marked downshift of the CS stretching and upshift of the NCN symmetric stretching by comparison of the SERS with the normal Raman spectrum of thiourea are clearly observed and interpreted by coordination of thiourea with tire iron surface through sulfur atom. The appearance of the low-frequency mode at ca. 283 cm(-1) assigned to the Fe-S vibration supports the assumption of S-coordination of thiourea. The orientation of thiourea molecules is assumed to be slightly inclined to the iron surface at an inter-mediate angle due to the observation of the SCNN out-of-plane bending band. Potential dependence of the SERS spectra shows that thiourea may interact more strongly with the iron surface at relatively positive potentials. Coadsorption of the supporting electrolyte anion ClO4- with thiourea has also been confirmed by the SERS spectra.