Reeves Kyle G, Dambournet Damien, Laberty-Robert Christel, Vuilleumier Rodolphe, Salanne Mathieu
Sorbonne Université, CNRS, UMR 7574, Physico-chimie des électrolytes et nanosystèmes interfaciaux, PHENIX Paris France
Réseau sur le Stockage Electrochimique de L'Energie (RS2E), FR CNRS 3459 80039 Amiens France.
RSC Adv. 2020 Mar 2;10(15):8982-8988. doi: 10.1039/c9ra10415a. eCollection 2020 Feb 27.
Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO with charge balance achieved the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a monolayer of water density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1 eV of the Fermi level for various steps throughout the simulation, and we determine that the variation in this visualization of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules.
化学掺杂和其他表面改性已被用于设计材料的整体性质，但其对表面结构以及由此产生的表面化学的影响往往未知。先前的工作成功地对锐钛矿型TiO进行了氟化处理，通过引入Ti空位而非Ti的还原实现了电荷平衡。我们在此的工作基于密度泛函理论分子动力学研究了这种具有阳离子空位的氟化钛酸盐与单层水之间的界面。我们仅计算模拟过程中各个步骤界面处那些原子以及费米能级1 eV范围内的态的投影态密度，并确定态密度可视化的这种变化是预测表面最可能发生反应位置的合理工具。特别是，我们得出结论，表面的水离解是影响锐钛矿（001）表面的主要机制，而氟化结构表面的态密度变化主要是通过水分子的吸附来影响的。
