An Ab-Initio Study on Mechanical Properties of Titanium Dioxide Single-Wall Nanotube

Titanium dioxide nanotubes (TiO2 NTs) exhibit superior biomechanical compatibility compared to artificial biomaterials. In this study, we employed density functional theory (DFT) calculations using the generalized gradient approximation (GGA) to determine the elastic-plastic regions and Young's moduli of TiO2 NTs. Following the optimization process, our findings reveal that the TiO bond lengths differ depending on whether they are inside or outside bonds, ranging from 1.85 to 2.05 angstrom. Notably, TiO2 NTs demonstrate a low elastic modulus of approximately 29-38GPa when subjected to strains between -2% and 2% along the central axis of the nanotube. Regarding the elastic-plastic regions, the first critical point (ec1) is reached at around 20% strain for the (8,8) TiO2 NT, suggesting that it will transition out of the elastic region faster than the others under uniaxial strain. Additionally, the total density of state (DOS) analysis indicates that all of these structures exhibit semiconductor properties.