Growth of undoped and Fe doped TiO2 nanostructures and their optical and photocatalytic properties

Undoped and Fe-doped TiO2 nanostructures have been successfully grown on Pt-coated quartz and Si (100) substrates using vapor-liquid-solid (VLS) growth method. The scanning electron microscopy (SEM) image showed that TiO2 grew in nanowires (NWs) with diameters of 200-400 nm and lengths greater than 12 mu m. However, the morphology of Fe-doped TiO2 consists of chunk shaped nanoparticles (NPs). The X-ray diffraction analysis for undoped TiO2 NWs clearly showed the formation of tetragonal rutile TiO2, whereas for the Fe-doped TiO2 NPs it showed orthorhombic TiO2 phase and there are no crystalline peaks for iron or iron oxide. The refractive index and extinction coefficient values of undoped and Fe-doped TiO2 nanostructures were derived from the ellipsometric measurements. Enhanced photocatalytic activities were obtained for undoped and Fe-doped TiO2 nanostructures. The obtained results may find potential applications in optical devices and degradation of organic wastes.