基于第一性原理的铝/水界面腐蚀模型零电荷电位的确定
First Principles Determination of the Potential-of-Zero-Charge in an Alumina-coated Aluminum/Water Interface Model for Corrosion Applications
摘要：
大多数浸在水电解质中的金属表面都有几纳米厚的氧化物/氢氧化物表面层。这就导致了两种金属的存在|氧化物和氧化物|液体电解质界面，并且使得将原子长度尺度结构与电化学性质（诸如零电荷电位（PZC））相关联具有挑战性。PZC值已被证明与腐蚀的点蚀起始电位相关。本文采用大尺度密度泛函理论和从头算分子动力学方法计算了Al（111）的PZC| γ-Al（2）O（3）（110）|水双界面模型中的铝腐蚀。通过将涉及的多个界面划分为对总体功函数和电压具有附加贡献的二元组分，我们预测该模型的PZC为-1.53 V vs. SHE。我们还计算了氧化物中氧空位等缺陷的轨道能级，这些缺陷是与点蚀相关的理论中的关键参数。我们预测，费米能级在PZC位于以上的氧空位，因此不带电的PZC的杂质缺陷水平。从PZC的估计，我们预测的电压需要创造净正电荷内的平带近似的氧空位。
英文摘要：
The surfaces of most metals immersed in aqueous electrolytes have a several-nanometer-thick oxide/hydroxide surface layer. This gives rise to the existence of both metal|oxide and oxide|liquid electrotlyte interfaces, and makes it challenging to correlate atomic length-scale structures with electrochemical properties such the potential-of-zero-charge (PZC). The PZC value has been shown to be correlated the pitting onset potential for corrosion. In this work, we conduct large-scale Density Functional Theory and ab initio molecular dynamics to calculate the PZC of a Al(111)|gamma-Al(2)O(3)(110)|water double-interface model within the context of aluminum corrosion. By partitioning the multiple interfaces involved into binary components with additive contributions to the overall work function and voltage, we predict the PZC to be -1.53 V vs. SHE for this model. We also calculate the orbital energy levels of defects like oxygen vacancies in the oxide, which are critical parameters in theories associated with pitting corrosion. We predict that the Fermi level at the PZC lies above the impurity defect levels of the oxygen vacancies, which are therefore uncharged at the PZC. From the PZC estimate, we predict the voltage needed to create oxygen vacancies with net positive charges within a flat-band approximation.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
