Atomistic Insight into the Electrochemical Double Layer of Choline Chloride–Urea Deep Eutectic Solvents: Clustered Interfacial Structuring

Abstract

Green, stable and wide electrochemical window deep eutectic solvents (DESs) are ideal candidates for electrochemical systems. However, despite several studies of their bulk properties, their structure and properties under electrified confinement are barely investigated, which hinders the widespread use of these solvents in electrochemical applications. In this letter, we explore the electrical double layer structure of 1:2 choline chloride-urea (Reline), with a particular focus on the electrosorption of the hydrogen

Catalyst–Electrolyte Interactions in Aqueous Reline Solutions for Highly Selective Electrochemical CO2 Reduction

“…At the DL, there exists a strong electrostatic repulsion between the negatively charged Ag foil and the negative pole of urea molecule, that is, the oxygen atom. This causes the C=O vector in the urea molecule to points towards the bulk . Although we did not observe a large change in capacitance of the Ag foil in KHCO 3 when urea was added (Figure A), the adsorbed urea in the XPS suggests a strong urea–surface interaction.…”

Nanolubrication in deep eutectic solvents

“…[51][52][53] This hypothesis is supported by recent simulations of the DES reline. Mamme et al 54 used molecular dynamics to simulate the structure of reline at neutral and charged interfaces. They found that at negative and positive potentials a Stern layer was present at the interface of choline cations or chloride anions respectively, but beyond this innermost layer all of the other layers were of mixed composition, albeit with some variation in charge density.…”

Water distribution at the electrified interface of deep eutectic solvents

“…This can be explained by the fact that at moderate polarization, the local intermolecular interaction between urea molecule and the other species (URE-Ch + , URE-Cl À and URE-H 2 O) becomes predominant, whereas for a high surface polarization the local intermolecular predominance is overtaken by the strongly enhanced external electrostatic interaction between the urea dipole and graphene. 66 Interdependency of the electric eld distribution and preferential adsorption of water It is well known that the electric potential oscillates in the EDLS region due to the overscreening phenomena and gradually damps out as a function of distance from the electrode surface. This results in the oscillation of the electric eld.…”