The interfacial lattice origin of anatase titanium dioxide by hydrothermal architecture

Abstract

The interfacial microstructure and defects formed during the growth of anatase TiO2 nanocrystalline by oriented attachment (OA) in the process of hydrothermal synthesis have been studied by using high-resolution transmission electron microscope (HRTEM) combined with theoretical simulation. In the {101} crystal plane of anatase TiO2 nanoparticles, it is easy to observe that the nanocrystal grains are attached to form large single crystals or twin structure through high resolution energy filtered images. At the initial stage of synthesis, obvious changes of interplanar spacing between crystal planes, lattice distortions or dislocations could be observed at the interfaces of those unstable grains. The analyses on the Burgers vector loop of dislocations conclude that the Burgers vectors are 1/2〈101〉. Furthermore, the simulated images and the atomic structure models based on the captured images are in perfect agreement with the original ones. Meanwhile, the OA of anatase TiO2 nanoparticles on {112} crystal plane is also observed and twin crystals are formed along 〈311〉 crystallographic zone axis including dislocations at the interfaces. However, due to the damages of electron irradiation, few high-resolution images of these grains have been obtained. Analysis of these interfacial structures provide a new idea to understand the formation and transformation of the microstructure of anatase TiO2 nanoparticles during hydrothermal synthesis.