Souda Ryutaro, Aizawa Takashi, Sugiyama Naoyuki, Takeguchi Masaki
Transmission Electron Microscopy Station, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
Center for Functional Sensor & Actuator, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
Phys Chem Chem Phys. 2020 Sep 23;22(36):20515-20523. doi: 10.1039/d0cp01897j.
We have investigated how nucleation and growth processes of ice are influenced by interfacial molecular interactions on some oxide surfaces, such as rutile TiO2(110), TiO2(100), MgO(100), and Al2O3(0001), based on the diffraction patterns of electrons transmitted through ice crystallites under the experimental configuration of reflection high energy electron diffraction (RHEED). The cubic ice Ic grows on the TiO2(110) surface with the epitaxial relationship of (110)Ic//(110)TiO2 and [001]Ic//[11[combining macron]0]TiO2. The epitaxial ice growth tends to be disturbed on the TiO2(110) surface under the presence of oxygen vacancies and adatoms. The result is not simply ascribable to small misfit values between TiO2 and ice Ic lattices (∼2%) because ice grains are formed randomly on TiO2(100). No template effects are identified during ice nucleation on the pristine MgO(100) and Al2O3(0001) surfaces either. The water molecules are chemisorbed weakly on these surfaces as a precursor to dissociation via the acid-base interaction. Such anchored water species act as an inhibitor of epitaxial ice growth because the orientation flexibility of physisorbed water during nucleation is hampered at the interface by the preferential formation of hydrogen bonds.
基于反射高能电子衍射（RHEED）实验配置下透过冰晶的电子衍射图案，我们研究了冰的成核和生长过程如何受到某些氧化物表面（如金红石型TiO₂(110)、TiO₂(100)、MgO(100)和Al₂O₃(0001)）上的界面分子相互作用的影响。立方冰Ic在TiO₂(110)表面生长，其外延关系为(110)Ic//(110)TiO₂和[001]Ic//[11[横线]0]TiO₂。在存在氧空位和吸附原子的情况下，外延冰生长在TiO₂(110)表面往往会受到干扰。该结果不能简单地归因于TiO₂和冰Ic晶格之间较小的失配值（约2%），因为冰粒在TiO₂(100)上随机形成。在原始的MgO(100)和Al₂O₃(0001)表面上的冰成核过程中也未发现模板效应。水分子通过酸碱相互作用作为解离的前驱体在这些表面上发生弱化学吸附。这种锚定的水物种作为外延冰生长的抑制剂，因为在成核过程中物理吸附水的取向灵活性在界面处因优先形成氢键而受到阻碍。
