Ab initio modeling of TiO2 nanotubes

Abstract

TiO₂ nanotubes constructed from a lepidocrocite-like TiO₂ layer were investigated with ab initio methods employing the periodic CRYSTAL code. The dependence of strain energies, structural and electronic properties on the tube diameter was investigated in the 18–57 Å range. Nanotubes constructed by a (0,n) rollup proved to be the most stable at all diameters. All three types of rollup undergo significant reconstruction at diameters <25 Å. All investigated structures possess a high (∼5.4 eV) band gap compared to bulk TiO₂ phases (3.96 and 4.63 eV for rutile and anatase calculated with the same functional and basis set).