共查询到16条相似文献,搜索用时 300 毫秒
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现场拉曼光谱研究乙腈在金电极上的解离吸附行为 总被引:2,自引:1,他引:1
利用共焦显微拉曼系统、结合合适的电极表面粗糙方法研究了非水体系 0 1mol/LLiClO4 /CH3CN溶液中 ,乙腈分子在金表面的吸附和解离行为。结果表明非水体系中乙腈可在金表面发生还原反应 ,产物CN- 离子与电极表面作用形成的表面配合物可在较宽的电位区间吸附于电极表面。溶液中的微量水、激光照射以及电极电位均对该反应有较大的影响。通过拉曼谱图的比较得出乙腈分子解离出的CN- 在金电极表面比在银电极表面有更强的吸附作用。 相似文献
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用Nd:YAG激光器在二次去离子水中烧蚀银片,制备出了尺度分布均匀、并且具有很好的稳定性的"化学纯净"的Ag胶体系,并在电化学体系中将这种银胶沉积在粗糙的银电极表面,研究了胞嘧啶分子吸附在沉积Ag纳米颗粒电极表面随电极电位改变的表面增强拉曼光谱(SERS)。分析表明:(1)沉积银纳米颗粒的电极将金属电极与金属溶胶体系各自的优势很好的结合起来,形成了一种高效的SERS活性基底。(2)胞嘧啶在沉积银颗粒的电极表面以N3位竖直吸附,并且随着电位的负移,大多数SERS峰的位置发生了红移,表明胞嘧啶在电极表面吸附作用减弱。 相似文献
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吡啶羧酸在银电极表面随电极电位变化的表面增强拉曼光谱研究(英文) 总被引:1,自引:1,他引:0
WENRui FANGYan 《光散射学报》2005,17(1):64-66
本文通过表面增强拉曼散射研究了三种不同构型的吡啶羧酸—皮考酸、异烟酸和烟酸在粗糙银电极表面上的吸附形态随电极电位的变化关系。大量的表面结构信息可从丰富的表面拉曼信号及其随电极电位相应的变化而获得。分析表明在电极电位负移过程中皮考酸分子一直采取通过羧基和苯环上的N原子侧立吸附在银电极表面,与之不同的是,异烟酸分子和烟酸分子在表面的吸附状态都随电位改变发生了变化,我们对此进行了分析和解释 相似文献
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分别在粗糙银电极和银纳米颗粒修饰银电极上得到了哌啶分子的表面增强拉曼(SERS)光谱。哌啶在银电极与银纳米颗粒修饰的银电极上的SERS谱有很大的区别,分析认为是由于哌啶在不同基底上的吸附方式不同所引起的,据此建立了哌啶吸附在银颗粒表面的两种模型,用DFT-B3PW91-lanl2dz方法计算了两种模型的拉曼频移,通过与实验结果比较说明了哌啶分子主要通过N原子的孤对电子竖直吸附在粗糙银电极表面,而在银纳米颗粒修饰的银电极上则以平行吸附方式为主。 相似文献
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The surface enhanced Raman scattering (SERS) spectra of piperidine in silver colloid solution, on roughened silver electrode
and on roughened silver electrode modified with silver nanoparticles were studied, and the high-quality SERS spectra of piperidine
on roughened silver electrode modified with silver nanoparticles were obtained for the first time. Surface selection rules
derived from the EM enhancement model were employed to deduce piperidine orientations on the different surfaces. On the basis
of this, two models of piperidine adsorbed on the surface of the silver nanoparticles were built, and DFT-B3PW91/LanL2dz was
applied to calculate the Raman frequencies. It proves that, at higher potential values, the piperidine is perpendicularly
standing on the roughened silver electrode surface though its lone-electron pair, but in silver colloid solution and on the
silver nanoparticles modified silver electrode the piperidine molecular lies flat on the silver surface. In the meantime,
the potential dependent SERS of piperidine on the modified electrode were studied. 相似文献
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本文报道了非水电化学体系中激光照射时间对咪唑在甲醇溶剂中吸附在电化学粗糙了的银电极表面上的表面增强拉曼散射(SERS)效应的影响及咪唑吸附在银电极表面上的SERS谱的连续背景的研究。结果表明,甲醇介质中咪唑吸附在银电极表面上的SERS谱强度随激光照射时间而变化,并且咪唑在甲醇介质中的SERS谱背景较强。初步探讨了咪唑吸附在银电极表面上的SERS效应的增强机制。 相似文献
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Polythiophene derivative films have been synthesized on electrochemically roughened silver, gold, and copper electrodes by anodic oxidation of the corresponding monomers. Surface‐enhanced Raman scattering (SERS) analyses of these coatings led to high‐quality spectra with high signal‐to‐noise ratios. In contrast with platinum, the use of SERS‐active metals allowed the observation of important changes in the positions, widths, and relative intensities of the Raman bands during the polymer doping‐dedoping process. In situ SERS investigations revealed that the modifications in the spectral features, when the polymer oxidation degree is progressively increased, are due to a transition from the aromatic to the quinoid structure and to an increase of structural defects along the polymer chains. Moreover, in the case of soluble polyalkylthiophene films, SERS analyses were also carried out using colloidal silver solutions. Despite the very low polymer concentration and the mild experimental conditions used in these experiments, a large amplification of the Raman signal took place. Two other methods for obtaining polybithiophene–silver composite films are reported. In these cases, thanks to the silver particles, the polymer displays a SERS effect, which greatly improves the signal‐to‐noise ratio of the Raman spectra, thus allowing a much better vibrational analysis of both doped and undoped states. 相似文献
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