[Surface enhanced Raman spectroscopic studies on the coadsorption of N-methylimidazole and 2,2'-bipyridine at Cu electrode].

The adsorption behavior and coadsorption of N-methylimidazole(NMIM) and 2,2'-bipyridine(2,2'-bipy) at copper electrode were investigated by in situ electrochemical surface enhanced Raman spectroscopy(SERS) in the acetonitrile solution.In situ SERS studies revealed that NMIM can adsorb stably onto Cu electrode in a quite different potential range,but the potential range for adsorbing 2,2'-bipy is narrow.With the introduction of 2,2'-bipy into the solution,the SERS could be divided into three parts:(a) under-0.8 V,NMIM molecule adsorption,(b) near the open potential,2,2'-bipy molecule adsorption with cis-conformation,(c) at positive potential region,both NMIM and 2,2'-bipy were coadsorbed at Cu surface,and the SERS data also suggested that the NMIM bound to copper surface with a tilted orientation,while the 2,2'-bipy was adsorbed through cis-conformation to the surface.