现场拉曼光谱研究乙腈在金电极上的解离吸附行为

In-situ Raman Spectroscopy Studies on the Dissociation Behavior of Acetonitrile at Gold Electrodes

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。

By utilizing SERS (surface-enhanced Raman scattering) technique combined with proper surface roughening procedures and a confocal microprobe Raman system, the dissociation and adsorption of acetonitrile molecule on the roughened gold electrodes was investigated in non-aqueous acetonitrile system. It is found that at the negative potential acetonitrile molecule can be partially dissociated to cyanide (CN-), and the complex from the interaction between cyanide and the surface of the electrode could be adsorbed on the surface of the electrode over a wide potential range. At the same time, the trace water in the solution, irradiation of the laser and potential have great influence on the decomposition of acetonitrile. By comparing the Raman spectral features with each other, one can assume that the dissociated cyanide of acetonitrile more strongly interacts with the gold electrode than the silver electrode.