At an electrode surface, the build-up of electrical charge, driven by a potential difference (or voltage), produces a strong electric field that drives molecular rearrangements in the electrolyte next to the electrode. Users and staff at the Molecular Foundry have developed a method to not only look at the molecules next to an electrode’s surface, but to determine how their arrangement changes depending on the voltage.
With gold as a chemically inert electrode, and slightly-saline water as an electrolyte, the team used a new twist on x-ray absorption spectroscopy (XAS), in concert with large molecular dynamics simulations, to probe the interface and show how the interfacial molecules are arranged. This combined experimental and theoretical approach is essential for a fundamental understanding of electrochemical reactions, with applications to electrocatalysis, photochemistry, energy storage and others.
