【摘要】 本文采用经典分子动力学对KOH溶液与锐钛矿相TiO₂（001）面的界面相互作用进行了模拟计算,结果表明,K⁺主要分布于TiO₂（001）表面相邻两桥氧原子的中间位置并与之成键;K⁺在TiO₂表面的吸附使其配位数和近表面扩散系数减少,并在近表面处形成有序结构。以KOH溶液离子数密度为基础计算得到液相部分的电荷、电场、电势分布,为了分析KOH对界面性质的影响,将只考虑水分子的溶液体系和纯水体系结果进行对比,结果发现,溶液的电荷密度和电场分布曲线峰值增大,电势收敛较慢,其原因为K⁺集中在表面而OH^-随机分布于整个体系,由此造成体相阴离子相对过剩。更多还原

【Abstract】 In this work, the interaction between anatase TiO₂（001） surface and KOH solution is studied by molecular dynamics simulations. Most of K⁺ ions are shown to adsord at two bidentate sites, between two bridging oxygens in adjacent rows on the crystal surface. In addition, the coordination number and diffusion coefficient of K⁺ are decreased due to its adsorption on TiO₂,resulting in an ordered structure in the interface. Based on the number density of K⁺, O^2-and H⁺,the interfacial electrostatic properties are analyzed. In order to obtain the effect of KOH on the interface, the electrostatic properties of H₂ O in solution are considered and compared with pure water system. The peaks of the charge density and the electric field distribution curves of KOH solution increase and the convergence of its potential becomes slow. The reason is that potassium ions are concentrated on the interface while hydroxyl ions are randomly distributed in the whole system, which lead to relative excess of anions in the bulk.更多还原