Thinnest Titanium Dioxide Nanowires Assembled by Ti₂O₄ Building Blocks

We show by performing density functional theory calculations that the dimer of titanium dioxide (TiO 2 ) molecule, Ti 2 O 4, is qualified for serving as a basic building block of TiO 2 nanostructures owing to its structural stability and appropriate growth activity. In particular, the two thinnest titanium dioxide nanowires, as the prototypes of TiO 2 nanostructures, have been assembled and proved to be geometrically graceful and dynamically stable. Calculated results show that the size and shape of TiO 2 nanowires have important effects on their structural stabilities and energy gaps, proposing that tailoring the size and shape of TiO 2 nanowires may be an effective way to modulate the band gap and finally improve their optical properties.