Structure and capacitance of an electric double layer of an asymmetric valency dimer electrolyte: A comparison of the density functional theory with Monte Carlo simulations
Here, the density functional theory is applied to a study of the structure and differential capacitance of a planar electric double layer formed by a valency asymmetric mixture of charged dimers and monomers. The dimer consists of two tangentially tethered hard spheres of equal diameters of which one is charged and the other is neutral, while the monomer is a charged hard sphere of the same size. The dimer electrolyte is next to a uniformly charged, smooth planar electrode. The electrodeparticle singlet distributions, the mean electrostatic potential, and the differential capacitance for the model double layer are evaluated for a 2:1/1:2 valency electrolyte at a given concentration. Important consequences of asymmetry in charges and in ion shapes are (i) a finite, nonzero potential of zero charge, and (ii) asymmetric shaped 2:1 and 1:2 capacitance curves which are not mirror images of each other. Comparisons of the density functional results with the corresponding Monte Carlo simulations show the theoretical predictions to be in good agreement with the simulations overall except near zero surface charge.
 Authors:

^{[1]};
^{[2]};
^{[3]};
^{[3]};
^{[4]};
^{[2]}
 Brigham Young Univ., Provo, UT (United States)
 Univ. of Puerto Rico, San Juan (Puerto Rico)
 Adam Mickiewicz Univ. of Poznan, Poznan (Poland)
 Univ. of California, Riverside, CA (United States)
 Publication Date:
 Grant/Contract Number:
 AC0500OR22725
 Type:
 Accepted Manuscript
 Journal Name:
 Journal of Molecular Liquids
 Additional Journal Information:
 Journal Volume: 228; Journal Issue: C; Journal ID: ISSN 01677322
 Publisher:
 Elsevier
 Research Org:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Sponsoring Org:
 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC22)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Planar electric double layer; Density functional theory; Anisotropic ion shape; Asymmetric valencies
 OSTI Identifier:
 1399239
 Alternate Identifier(s):
 OSTI ID: 1413809
Henderson, Douglas, SilvestreAlcantara, Whasington, Kaja, Monika, Lamperski, Stanislaw, Wu, Jianzhong, and Bhuiyan, Lutful Bari. Structure and capacitance of an electric double layer of an asymmetric valency dimer electrolyte: A comparison of the density functional theory with Monte Carlo simulations. United States: N. p.,
Web. doi:10.1016/j.molliq.2016.08.051.
Henderson, Douglas, SilvestreAlcantara, Whasington, Kaja, Monika, Lamperski, Stanislaw, Wu, Jianzhong, & Bhuiyan, Lutful Bari. Structure and capacitance of an electric double layer of an asymmetric valency dimer electrolyte: A comparison of the density functional theory with Monte Carlo simulations. United States. doi:10.1016/j.molliq.2016.08.051.
Henderson, Douglas, SilvestreAlcantara, Whasington, Kaja, Monika, Lamperski, Stanislaw, Wu, Jianzhong, and Bhuiyan, Lutful Bari. 2016.
"Structure and capacitance of an electric double layer of an asymmetric valency dimer electrolyte: A comparison of the density functional theory with Monte Carlo simulations". United States.
doi:10.1016/j.molliq.2016.08.051. https://www.osti.gov/servlets/purl/1399239.
@article{osti_1399239,
title = {Structure and capacitance of an electric double layer of an asymmetric valency dimer electrolyte: A comparison of the density functional theory with Monte Carlo simulations},
author = {Henderson, Douglas and SilvestreAlcantara, Whasington and Kaja, Monika and Lamperski, Stanislaw and Wu, Jianzhong and Bhuiyan, Lutful Bari},
abstractNote = {Here, the density functional theory is applied to a study of the structure and differential capacitance of a planar electric double layer formed by a valency asymmetric mixture of charged dimers and monomers. The dimer consists of two tangentially tethered hard spheres of equal diameters of which one is charged and the other is neutral, while the monomer is a charged hard sphere of the same size. The dimer electrolyte is next to a uniformly charged, smooth planar electrode. The electrodeparticle singlet distributions, the mean electrostatic potential, and the differential capacitance for the model double layer are evaluated for a 2:1/1:2 valency electrolyte at a given concentration. Important consequences of asymmetry in charges and in ion shapes are (i) a finite, nonzero potential of zero charge, and (ii) asymmetric shaped 2:1 and 1:2 capacitance curves which are not mirror images of each other. Comparisons of the density functional results with the corresponding Monte Carlo simulations show the theoretical predictions to be in good agreement with the simulations overall except near zero surface charge.},
doi = {10.1016/j.molliq.2016.08.051},
journal = {Journal of Molecular Liquids},
number = C,
volume = 228,
place = {United States},
year = {2016},
month = {8}
}