Replica RISM molecular solvation theory for electric double layer in nanoporous materials

TL;DR

This paper extends the 3D-RISM-KH molecular solvation theory to predict and analyze the structure, thermodynamics, and electrochemistry of electrolyte solutions in nanoporous materials, with applications to supercapacitors and electrosorption cells.

Contribution

It introduces the Replica RISM-KH-VM theory for nanoporous systems, accounting for chemical specificity, steric effects, and electric double layer phenomena.

Findings

Successfully modeled electrolyte behavior in nanopores.

Revealed the influence of ion specificity and surface chemistry.

Provided insights into electric double layer mechanisms in nanoporous materials.

Abstract

Applications of 3D-RISM-KH molecular solvation theory range from solvation energy of small molecules to phase behavior of polymers and biomolecules. It predicts the molecular mechanisms of chemical and biomolecular systems. Replica RISM-KH-VM molecular solvation theory predicts and explains the structure, thermodynamics, and electrochemistry of electrolyte solutions sorbed in a nanoporous material. It was tested on nanoporous carbon supercapacitors with aqueous electrolyte and nanoporous electrosorption cells. The mechanisms in these systems are steered by the electric double layer potential drop across the Stern layer at the nanopores surface and the Gouy-Chapman layer averaged over the nanoporous material, the osmotic term due to the ionic concentrations difference in the two nanoporous electrodes and in the electrolyte solution outside, and the solvation chemical potentials of sorbed ions averaged over the nanoporous material. The latter strongly depends on chemical specificity of ions, solvent, surface functional groups, and steric effects for solvated ions confined in nanopores.