银电极表面上C60薄膜的表面增强拉曼光谱研究

在银电极表面形成一层C60薄膜,分别在乙腈溶液和水溶液中进行表面增强拉曼光谱(SERS)研究并将两者进行比较,从而消除了溶液中的C60干扰表面吸附C60的SERS谱图的可能性.研究结果表明,C60分子对称性的降低导致SERS谱峰发生了分裂;表面电磁场的作用使得光谱选律在SERS效应中被拓宽,产生了新的拉曼谱峰.该结果与团簇吸附在粗糙银电极表面的C60分子的研究结果相似.与之不同的是在乙腈溶液和水溶液中的SERS谱图的低波数区内分别在348和311 cm-1左右出现一个新峰,经过分析可认为该峰与C60-金属基底的相互作用有关.

Study on Surface-Enhanced Raman Spectroscopy of C60 Films on Ag Electrodes

The thin films of C60 on Ag electrodes were studied by in situ surface-enhanced Raman spectroscopy (SERS) in acetonitrile solution and water solution respectively. The influence of C60 from bulk solution on the SERS of the adsorbed C60 was removed by pre-forming C60 films on the electrode. The results indicate that the split of some relevant Raman bands was attributed to the loss of vibrational degeneracy due to the lowering of the C60 molecular symmetry. Moreover, the surface selection rule was extended because of the influence of the surface electromagnetic field in which some forbidden modes became Raman-active. The results were similar to that of C60 molecules adsorbed on Ag electrode in the solution of C60. A weak band at about 348 and 311 cm-1 was observed for the C60 films in acetonitrile solution and in aqueous solution respectively, which could be assigned to the interaction of C60 and Ag electrode surface.