Toward Hyphenated In Situ Infrared and Raman Spectroscopies in Interfacial Electrochemistry

Abstract

To address the pressing demand for hyphenated in situ characterization of the electrode–electrolyte interfaces at the molecular level, we report herein a technical note to demonstrate the hyphenation of in situ electrochemical surface-enhanced infrared absorption spectroscopy (SEIRAS) and shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS). The core setup incorporates a top-down configured Raman optic fiber head loaded on a 3-dimension positioning module and a bottom-up configured attenuated total reflection infrared spectroscopy (ATR-IR) spectroelectrochemical cell accommodated in a custom-designed optical accessory. The feasibility of this integrated design is initially validated by the simultaneous measurement of two model systems, namely, potential dependent adsorption of pyridine on a Au film electrode and the CO₂ reduction reaction on a Cu film electrode by in situ SEIRAS and SHINERS, yielding distinct and complementary spectral information.