In situ ion irradiation of amorphous TiO2 nanotubes

Understanding of structural and morphological evolution in nanomaterials is critical in tailoring their functionality for applications such as energy conversion and storage. Here, we examine irradiation effects on the morphology and structure of amorphous TiO2 nanotubes in comparison with their crystalline counterpart, anatase TiO2 nanotubes, using high-resolution transmission electron microscopy (TEM), in situ ion irradiation TEM, and molecular dynamics (MD) simulations. Anatase TiO2 nanotubes exhibit morphological and structural stability under irradiation due to their high concentration of grain boundaries and surfaces as defect sinks. On the other hand, amorphous TiO2 nanotubes undergo irradiation-induced crystallization, with some tubes remaining only partially crystallized. The partially crystalline tubes bend due to internal stresses associated with densification during crystallization as suggested by MD calculations. These results present a novel irradiation-based pathway for potentially tuning structure and morphology of energy storage materials.

Automated summary

Understanding the evolution of structure and morphology in nanomaterials is crucial for controlling their functionality. In this study, the effects of irradiation on the morphology and structure of amorphous and anatase TiO2 nanotubes were investigated. The anatase TiO2 nanotubes showed stability under irradiation due to their grain boundaries and surfaces, while the amorphous TiO2 nanotubes underwent irradiation-induced crystallization, with partially crystallized tubes bending due to internal stresses. These findings provide a new pathway for controlling the structure and morphology of energy storage materials.