(Invited) Cations at a Solid-Liquid Interface: A Second Harmonic Generation Investigation

Abstract

When an electrode contacts an electrolyte, an interfacial electric field forms. This interfacial field can polarize the electrode’s surface and nearby molecules, but its effect can be reversed by applying external potential. One method for quantifying this effect is the phase-sensitive second harmonic generation (PS-SHG) technique. We present our PS-SHG investigation of the Pt/water interface, where we examine the impact of the electrolyte chemistry on the electrical double layer (EDL). We will discuss how switching cations in alkaline electrolytes can affect the solid-liquid interface, in particular, the behavior of interfacial water. Our work provides a tool for quantifying the interfacial electric field at an electrode-electrolyte interface and shows the possibility of how cations can modify the EDL.