Influence of anisotropic ion shape, asymmetric valency, and electrolyte concentration on structural and thermodynamic properties of an electric double layer
| Autor: | Kaja, M., Lamperski, S., Silvestre-Alcantara, W., Bhuiyan, L. B., Henderson, D. |
|---|---|
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Condens. Matter Phys., 2016, vol. 19, No. 1, 13804 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.5488/CMP.19.13804 |
| Popis: | Grand canonical Monte Carlo simulation results are reported for an electric double layer modelled by a planar charged hard wall, anisotropic shape cations, and spherical anions at different electrolyte concentrations and asymmetric valencies. The cations consist of two tangentially tethered hard spheres of the same diameter, $d$. One sphere is charged while the other is neutral. Spherical anions are charged hard spheres of diameter $d$. The ion valency asymmetry 1:2 and 2:1 is considered, with the ions being immersed in a solvent mimicked by a continuum dielectric medium at standard temperature. The simulations are carried out for the following electrolyte concentrations: 0.1, 1.0 and 2.0 M. Profiles of the electrode-ion, electrode-neutral sphere singlet distributions, the average orientation of dimers, and the mean electrostatic potential are calculated for a given electrode surface charge, $\sigma$, while the contact electrode potential and the differential capacitance are presented for varying electrode charge. With an increasing electrolyte concentration, the shape of differential capacitance curve changes from that with a minimum surrounded by maxima into that of a distorted single maximum. For a 2:1 electrolyte, the maximum is located at a small negative $\sigma$ value while for 1:2, at a small positive value. Comment: 10 pages, 6 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|