Toward an Accurate Modeling of Ionic Liquid–TiO2 Interfaces

Structural properties of the ionic liquids 1-ethyl-3-methylimidazolium thiocyanate and tetracyanoborate at the anatase (101) surface are of crucial interest for energy harvesting and storage devices, but their investigation via molecular dynamics requires large simulation cells. Thus, two classical interaction potentials with and without polarization effects were parametrized in order to accurately model the interface between the liquid and solid. The parameters were fitted to match ab initio reference interaction energies. Application of the generated force field to model the interface is demonstrated. The adsorption profiles of the ionic liquid’s components reveal a very dense surface layer with an excess of cations, which has some possible implications for the use of the ionic liquids as electrolytes, for example in solar cells.