Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
J Colloid Interface Sci. 2010 Jan 1;341(1):143-52. doi: 10.1016/j.jcis.2009.09.002. Epub 2009 Sep 6.
An analysis of surface potential nonlinearity (psi(0)) at metal oxide/electrolyte interfaces is presented. By using grand canonical Monte Carlo simulations of a simple lattice model of an interface, we show that 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 psi(0)-nonlinearity: one based on perturbative expansion of the Gibbs free energy and another based on the assumption of the pH dependence of surface potential slope. The theoretical analysis based on our new potential form gives excellent performance in extreme pH regions, where classical formulae for psi(0) are unjustified. 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 [6].
本文分析了金属氧化物/电解质界面的表面电位非线性（psi(0)）。通过对金属氧化物电极的非 Nernst 响应，我们使用界面简单晶格模型的巨正则蒙特卡罗模拟，表明离子强度以及表面位密度与 psi(0)非线性之间存在相关性。我们提出了两种处理 psi(0)-非线性的方法：一种基于吉布斯自由能的微扰展开，另一种基于表面电位斜率随 pH 值变化的假设。基于我们新的势能形式的理论分析在极端 pH 区域表现出色，而经典的 psi(0)公式在这些区域是不合理的。新公式是通用的，不依赖于任何基本假设。因此，它可以直接应用于实验表面电位测量，包括单晶的单个表面的测量，我们将 Kallay 和 Preocanin [6] 报告的数据应用于该公式。
