Surface-Enhanced Raman Microspectroscopy at Electrode Surfaces

Abstract

Surface-enhanced Raman microspectroscopy has been developed as a technique for characterizing processes occurring at the electrode/electrolyte interface. A spectroelectrochemical cell was designed to obtain Raman spectra of electrochemical species with the use of microscope optics, which allowed unambiguous placement of the laser focus at the electrode surface with spatial resolution on the order of 1 µm. It was also possible to visually inspect the surface morphology of the electrode with the use of the Raman microscope in the reflected-light mode. The capabilities of the spectroelectrochemical cell were demonstrated by observation of surface-enhanced Raman scattering (SERS) for a variety of model systems (pyridine, pyridinium ion, potassium cyanide) with the use of silver, copper, and nickel electrodes. The electrochemical behavior of a commercially important gold electroplating process is also reported.