Simultaneous Raman and reflection UV/Vis absorption spectroelectrochemistry

In the present work, a new combination of Raman and ultraviolet and visible (UV/Vis) absorption spectroelectrochemistry in reflection mode is proposed. The new experimental setup allows obtaining the two kinds of spectroscopic data without interferences concomitantly with the electrochemical information. To the best of our knowledge, it is the first time to report the simultaneous obtention of electrochemical, electronic, and vibrational information in the same experiment. This new combination provides time-resolved information about the processes that are taking place on the electrode/solution interface which has significant implications in different fields of chemistry, such as modification of electrodes, studies of electrocatalytic reaction mechanisms, development of sensors, among others. Two different systems were used to demonstrate the advantages and capabilities of the brand-new technique, namely, the oxidation of potassium ferrocyanide, an out-sphere system that is usually employed in the validation of SEC techniques, and the electrochemical-surface enhanced Raman spectroscopy (EC-SERS) detection of crystal violet by in-situ formation of the silver SERS substrate, where the UV/Vis spectra were used to follow the formation of the SERS substrate, whereas the Raman response of a probe molecule was used to confirm either the formation of a nanostructured surface and to obtain the fingerprint of the molecule with a high time resolution. The brand-new experimental setup has shown to be useful, versatile, robust, compact, and easy to use for future applications.