Atomistic investigation into the mechanical behaviour of crystalline and amorphous TiO2 nanotubes

Y Xu and MC Wang and N Hu and J Bell and C Yan, RSC ADVANCES, 6, 28121-28129 (2016).

DOI: 10.1039/c5ra27268h

Titanium dioxide (TiO2) nanotubes are appealing to research communities due to their excellent functional properties. However, there is still a lack of understanding of their mechanical properties. In this work, we conduct molecular dynamics (MD) simulations to investigate the mechanical behaviour of rutile and amorphous TiO2 nanotubes. The results indicate that the rutile TiO2 nanotube has a much higher Young's modulus (similar to 800 GPa) than the amorphous one (similar to 400 GPa). Under tensile loading, rutile nanotubes fail in the form of brittle fracture but significant ductility (up to 30%) has been observed in amorphous nanotubes. This is attributed to a unique 'repairing' mechanism via bond reconstruction at under-coordinated sites as well as bond conversion at over-coordinated sites. In addition, it is observed that the fracture strength of rutile nanotubes is strongly dependent on their free surfaces. These findings are considered to be useful for development of TiO2 nanostructures with improved mechanical properties.

Return to Publications page