SURFACE-ENHANCED RAMAN-SPECTROSCOPIC STUDIES ON SILVER ELECTRODES IN THE PRESENCE OF 2-MERCAPTOPYRIMIDINE

Abstract

Surface-enhanced Raman spectroscopy (SERS) was applied to the study of silver electrodes in the presence of 2-mercaptopyrimidine (2MP) over a wide electrode potential range from -0.3 to -1.8 V (vs. SCE), The spectra reveal that in neutral solution 2MP was adsorbed perpendicularly on the silver electrode via its sulphur atom at potentials more positive than -1.1 V and was electrochemically reduced at more negative potentials, The significant dependence of the SERS spectra on the solution pH and the time-resolved SERS results suggest that hydrooligomerization of 2AMP may take place during the electrochemical reduction process, It has been shown that SERS can be used as a unique tool to study structural changes of electrochemical interfaces through detailed molecular level analyses in the electrode potential region of hydrogen evolution.