Morphology Control of Single Crystalline Rutile TiO2 Nanowires

Nano-scaled metal oxides have been attractive materials for sensors, photocatalysis, and dye-sensitization for solar cells. We report the controlled synthesis and characterization of single crystalline TiO2 nanowires via a catalyst-assisted vapor-liquid-solid (VLS) and vapor-solid (VS) growth mechanism during TiO powder evaporation. Scanning electron microscope (SEM) and transmission electron microscope (TEM) studies show that as grown TiO, materials are one-dimensional (ID) nano-structures with a single crystalline rutile phase. Also, energy-dispersive X-ray (EDX) spectroscopy indicates the presence of both Ti and O with a Ti/O atomic ratio of 1 to 2. Various morphologies of single crystalline TiO2 nano-structures are realized by controlling the growth temperature and flow rate of carrier gas. Large amount of reactant evaporated at high temperature and high flow rate is crucial to the morphology change of TiO2 nanowire.