Solvothermal synthesis of ultralong single-crystalline TiO2 nanowires

Well-defined single crystalline TiO2 nanowires with diameters of 20–50 nm mostly and lengths of up to a few millimeters have been successfully synthesized by a simple, low-cost solvothermal process using the mixed solvent aqueous NaOH–ethanol. The as-synthesized nanowires are structurally uniform, of high purity and show perfect crystallinity. The growth mechanism of the nanowires has been investigated by following the growth steps of the samples at various reaction stages. The solvent significantly influences the morphology and the crystallization behavior of the final products. This novel approach may be applied to the large-scale fabrication of some other oxide nanowires.