Structure and Dynamics of a Confined Ionic Liquid. Topics of Relevance to Dye-Sensitized Solar Cells

Abstract

The behavior of a model ionic liquid (IL) confined between two flat parallel walls was studied at various interwall distances using computer simulations. The results focus both on structural and dynamical properties. Mass and charge density along the confinement axis reveal a structure of layers parallel to the walls that leads to an oscillatory profile in the electrostatic potential. Orientational correlation functions indicate that cations at the interface orient tilted with respect to the surface and that any other orientational order is lost thereafter. The diffusion coefficients of the ions exhibit a maximum as a function of the confinement distance, a behavior that results from a combination of the structure of the liquid as a whole and a faster molecular motion in the vicinity of the walls. We discuss the relevance of the present results and elaborate on topics that need further attention regarding the effects of ILs in the functioning of IL-based dye-sensitized solar cells.

Modern Theories of Carbon‐Based Electrochemical Capacitors

“…In addition, their orientation becomes more random as the distance from the electrode increases. Both the charge separation and ion orientation ordering penetrate about 1 nm into the bulk electrolyte, suggesting that the diffuse layer spans about 1 nm, in good agreement with other published works [135,137,141].…”

“…Most of the available modeling works on EDLs in ILs were performed in nanoslits featuring planar walls [135][136][137][138][139][140][141][142]. Given that an understanding of EDLs in ILs has only developed recently, most existing works focused on delineating the basic structure of the EDL and the dependence of its capacitance on electrode potential.…”

Specific distributions of anions and cations of an ionic liquid through confinement between graphene sheets

“…Hung et al investigated the effect of diameter of the multiwalled carbon nanotubes and the pore loading on the properties of the IL [BMIM][PF 6 ] [33]. Kohanoff et al [35] simulated the molten salt 1,3-dimethylimidazolium chloride confined between two flat parallel walls and showed a structure of layers parallel to the walls. Recently, Rajupt et al [30,32] performed MD simu l a t i o n s o f t h e 1 -e t h y l -3 -m e t h y l i m i d a z o l i u m bis-(trifluoromethanesulfonyl) imide IL inside a rutile (110) slit nanopore and a slit graphitic nanopore.…”

Probing the adsorption of methylimidazole at ionic liquids/Cu electrode interface by surface‐enhanced Raman scattering spectroscopy

“…[31 -33] For example, Pinilla et al [34] investigated the response of RTILs to an external electric field confined to a nanoslit by molecular dynamics simulations. For increasing field strengths, they found that a systematic rearrangement of the ions, mainly due to anion segregation toward the positive electrode and away from the negative wall, was the most noticeable structural change.…”