论文标题
在铝涂层的铝/水接口模型中确定零付费潜力的第一原理确定用于腐蚀应用
First Principles Determination of the Potential-of-Zero-Charge in an Alumina-coated Aluminum/Water Interface Model for Corrosion Applications
论文作者
论文摘要
浸入水性电解质中的大多数金属的表面具有几纳米厚的氧化物/氢氧化物表面层。这引起了金属|氧化物和氧化物|液体电晶体界面的存在，并且使将原子长度尺度结构与电化学特性（例如零电荷（PZC））相关联。 PZC值已被证明与腐蚀的点攻击潜力相关。在这项工作中，我们进行了大规模密度功能理论和从头算分子动力学，以计算Al（111）| gamma-al（2）o（2）o（3）（110）|在铝腐蚀背景下的水双接口模型。通过将涉及的多个接口对二进制组件进行分区，对整体工作功能和电压具有添加贡献，我们预计PZC为-1.53 V与她为此模型。我们还计算缺陷的轨道能水平，例如氧化物中的氧空位，这是与点腐蚀相关的理论中的关键参数。我们预测，PZC处的费米水平位于氧气空位的杂质缺损水平以上，因此在PZC处没有充电。从PZC估计值中，我们预测在平坦近似内产生具有净正电荷的氧气空位所需的电压。
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.
