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Title: Nonlinear response of the surface electrostatic potential formed at metal oxide/electrolyte interfaces. A Monte Carlo simulation study

Abstract

An analysis of surface potential nonlinearity at metal oxide/electrolyte interfaces is presented. By using Grand Canonical Monte Carlo simulations of a simple lattice model of an interface, we show a correlation exists between ionic strength as well as surface site densities and the non-Nernstian response of a metal oxide electrode. We propose two approaches to deal with the 0-nonlinearity: one based on perturbative expansion of the Gibbs free energy and another based on assumption of the pH-dependence of surface potential slope. The theoretical anal ysis based on our new potential form gives excellent performance at extreme pH regions, where classical formulae based on the Poisson-Boltzmann equation fail. The new formula is general and independent of any underlying assumptions. For this reason, it can be directly applied to experimental surface potential measurements, including those for individual surfaces of single crystals, as we present for data reported by Kallay and Preocanin [Kallay, Preocanin J. Colloid and Interface20 Sci. 318 (2008) 290].

Authors:
;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
973703
Report Number(s):
PNNL-SA-66514
Journal ID: ISSN 0021-9797; JCISA5; KC0303020; TRN: US201006%%946
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Colloid and Interface Science, 341(1):143-152; Journal Volume: 341; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ELECTROSTATICS; FREE ENTHALPY; ELECTROLYTES; OXIDES; INTERFACES; PERFORMANCE; SURFACE POTENTIAL; NONLINEAR PROBLEMS; MONTE CARLO METHOD

Citation Formats

Zarzycki, Piotr P., and Rosso, Kevin M.. Nonlinear response of the surface electrostatic potential formed at metal oxide/electrolyte interfaces. A Monte Carlo simulation study. United States: N. p., 2010. Web. doi:10.1016/j.jcis.2009.09.002.
Zarzycki, Piotr P., & Rosso, Kevin M.. Nonlinear response of the surface electrostatic potential formed at metal oxide/electrolyte interfaces. A Monte Carlo simulation study. United States. doi:10.1016/j.jcis.2009.09.002.
Zarzycki, Piotr P., and Rosso, Kevin M.. 2010. "Nonlinear response of the surface electrostatic potential formed at metal oxide/electrolyte interfaces. A Monte Carlo simulation study". United States. doi:10.1016/j.jcis.2009.09.002.
@article{osti_973703,
title = {Nonlinear response of the surface electrostatic potential formed at metal oxide/electrolyte interfaces. A Monte Carlo simulation study},
author = {Zarzycki, Piotr P. and Rosso, Kevin M.},
abstractNote = {An analysis of surface potential nonlinearity at metal oxide/electrolyte interfaces is presented. By using Grand Canonical Monte Carlo simulations of a simple lattice model of an interface, we show a correlation exists between ionic strength as well as surface site densities and the non-Nernstian response of a metal oxide electrode. We propose two approaches to deal with the 0-nonlinearity: one based on perturbative expansion of the Gibbs free energy and another based on assumption of the pH-dependence of surface potential slope. The theoretical anal ysis based on our new potential form gives excellent performance at extreme pH regions, where classical formulae based on the Poisson-Boltzmann equation fail. The new formula is general and independent of any underlying assumptions. For this reason, it can be directly applied to experimental surface potential measurements, including those for individual surfaces of single crystals, as we present for data reported by Kallay and Preocanin [Kallay, Preocanin J. Colloid and Interface20 Sci. 318 (2008) 290].},
doi = {10.1016/j.jcis.2009.09.002},
journal = {Journal of Colloid and Interface Science, 341(1):143-152},
number = 1,
volume = 341,
place = {United States},
year = 2010,
month = 1
}
  • In this feature article we discuss recent advances and challenges in measuring, analyzing and interpreting the electrostatic potential development at crystal/electrolyte interfaces. We highlight progress toward fundamental understanding of historically difficult aspects, including point of zero potential estimation for single faces of single crystals, the non-equilibrium pH titration hysteresis loop, and the origin of nonlinearities in the titration response. It has been already reported that the electrostatic potential is strongly affected by many second order type phenomena such as: surface heterogeneity, (sub)surface transformations, charge transfer reactions, and additional potential jumps at crystal face edges and/or Schottky barriers. Single-crystal electrode potentialsmore » seem particularly sensitive to these phenomena, which makes interpretation of experimental observations complicated. We hope that recent theory developments in our research group including an analytical model of titration hysteresis, a perturbative surface potential expansion, and a new surface complexation model that incorporates charge transfer processes will help experimental data analysis, and provide unique insights into the electrostatic response of nonpolarizable single-crystal electrodes.« less
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  • Canonical Monte Carlo simulations of the interaction between a uniformly charged spherical particle and a discretely charged planar surface in solutions of symmetric and asymmetric electrolytes were performed. To assess the nature of the interactions, the force exerted on the colloidal particle perpendicular to the planar surface was calculated. Attractive minima in the interaction force between the similarly charged surfaces reveal the occurrence of two phenomena: long-range attraction of electrostatic origin and short-range attraction due to depletion effects. The degree of electrostatic coupling determines the magnitude and range of like-charge attraction between the two surfaces.