Potential of zero charge and surface charging relation of metal-solution interphases from a constant-potential jellium-Poisson-Boltzmann model
Potential of zero charge and surface charging relation of metal-solution interphases from a constant-potential jellium-Poisson-Boltzmann model
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恒电位 Jellium-Poisson-Boltzmann 模型的零电荷电势和金属溶液界面相的表面充电关系
DOI：
10.1103/physrevb.101.125422
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发表时间：
2020-03-23
影响因子：
3.7
通讯作者：
Chen, Shengli
中科院分区：
文献类型：
--
作者：
Huang, Jun;Li, Peng;Chen, Shengli
零电荷电位（pzc），界面电化学中的一个基本概念，使用一个jellium-Poisson-Boltzmann模型重新审视。在恒电位描述的金属-溶液界面下，该模型能够计算表面充电关系（表面自由电荷密度作为电极电位的函数），然后确定pzc。微分双电层电容曲线的最小值所对应的电位低于由表面充电关系确定的pzc，这是由自由金属电子进入溶液相引起的。该模型进一步揭示了当溶液相和金属表面之间的真空间隙d变窄时，pzc减小。这与通常观察到的金属-溶液界面相的pzc低于由金属-真空界面相的功函数计算的pzc（后者对应于d = ∞）是一致的。多方面的作用所发挥的溶剂，包括静电屏蔽，极化子效应，和正交排斥，进行了分析。还讨论了离子的特异性吸附和电位依赖性d对表面电荷关系的影响。
The potential of zero charge (pzc), a fundamental concept in interfacial electrochemistry, is revisited using a jellium-Poisson-Boltzmann model. Under constant-potential description of the metal-solution interphase, this model is able to calculate the surface charging relation (surface free charge density as a function of the electrode potential) and then to determine the pzc therefrom. The potential corresponding to the minimum of differential double-layer capacitance curve is shown to be lower than the pzc determined from surface charging relation, which is caused by free metal electrons entering the solution phase. The model further reveals that the pzc decreases when the vacuum gap between the solution phase and the metal surface, d , becomes narrower. This is consistent with the common observation that the pzc of metal-solution interphase is lower than that calculated from the work function of metal-vacuum interphase (the latter corresponds to d = ∞ ). Multifaceted roles played by the solvent, including electrostatic screening, polaron effect, and orthogonalizational repulsion, are analyzed. Also discussed are the effects of specific adsorption of ions and potential-dependent d on the surface charging relation.