Probing Molecular Structures at Electrified Interfaces Using in-Situ Surface-Enhanced Raman Spectroscopy

The molecular scale understanding of electrode-electrolyte interfaces is significant, as interfacial molecular structures play a critical role in determining various properties such as capacitance and catalytic activity. However, the limited understanding exists on the interfaces, especially at a molecular level, due to difficulties to selectively probe the interfaces without an interference from the bulk. In this talk, I will present our recent observations on molecular configurations at electrified interfaces using in-situ surface-enhanced Raman spectroscopy (SERS). To be specific, we study interfaces of ionic liquids and aqueous electrolytes, considering they are promising candidates for various electrochemical applications. Our SERS spectra display a strong enough interface-sensitivity providing comprehensive information on a potential-dependence of ion configurations such as molecular position and orientation. We expect the molecular scale understandings provided by our studies are beneficial to a wide range of electrochemical applications including supercapacitors, batteries, and electrocatalysts.