| As good solvents for many materials, the aprotic solutions with its wider potential range have being electrochemically studied over 200 years. Since there is still a considerable lack of the molecular information in the non-aqueous solution, it is favorable to undertake the better understanding of solid/liquid interface in this region. Due to the developments of spectroscopy and spectroscopic technology, now we become to detect the electrochemical interface in molecule and atom level. So the deep research may be carried out by the combination of the electrochemical and spectroscopic methods. The discovery of the giant surface-enhanced Raman scattering (SERS) in the middle of 1 970s has presented the electrochemists with a powerful technique for probing the electrode/electrolyte interface in-situ. Most of the SERS studies were carried out in aqueous systems. Relatively smaller attention has been received in the study of non- aqueous systems not only because of the interference of the organic solvent but also the low detection sensitivity of the Ramanor. The advent of confocal microprobe Ramanor these years has made it possible to well probe the electrochemical/chemical process occurring at the metal/non-aqueous solution interface. At the same time, there is still lack of the explanation of the SERS mechanism. In the present thesis, The choice of acetonitrile is prompted by the fact that it is a good solvent and comarativele easily purified. Acetonitrile is probably one of the widely used organic solvents. The solvent character, the structure in the solid/liquid interface and the competitive adsorption have been studied in the non-aqueous solution on the surface of silver, gold and platinum electrodes. The detailed introduces are as follows: (1). The potential-dependent SER spectra assigned to the dissociation of acetonitrile molecule on the gold, silver and platinum electrodes were systematically obtained in acetonitrile solution with 0.1 M LiC1O4 for the first time. The results indicate the dissociation of acetonitrile is related to the laser illumination, potential and trance water in the solution. And CN from the dissociation of acetonitrile is more consumingly adsorbed on the gold and platinum electrodes than on the silver electrode. (2). In the non-aqueous acetonitrile solution, the SER spectra of imidazole and dimethyl sulfoxide are consistent. It is obvious that imidazole and dimethyl sulfoxide molecules take precedence of acetonitrile molecule adsorbing on the silver electrode. As the potential moves negatively, the former molecules get away from the electrode surface, so acetonitrile molecule can close with electrode surface and dissociate. Therefore, a conclusion may be drawn in the present system that the adsorption of DMSO postpones the dissociation of acetonitrile at the positive potential, and synchronously the dissociation of interfacial acetonitrile holds back the reorientation of the interfacial DMSO molecule at the negative potential. The same result occurs by Py molecule adsorbed on the platinum electrode in the non-aqueous acetonitrile solution including 0.05 M Py. (3). As an important C1 molecule, formic has the good foreground in the direct fuel cell. There have been many studies about the electro-catalyse and oxidation of formic on the surfaces of transition metals. However, most of them are carried out in the aqueous system. In this paper the good SER spectra were obtained in the non-aqueous formic and DMF, respectively. There are many differences between the present results an...
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