Shynthesis And Light Absorbance Of Titanium Dioxide Nanostructures

The design and synthesis of nanostructures are of both relevant theoretical andtechnological interest. The principal impetus toward fabricating nanodimensionalmaterials lies in the promise of achieving unique properties and superior performancesdue to their inherent nanoarchitectures.Titanium dioxide is a particularly versatile material with technological applications as aphotocatalyst, photovoltaic material, gas sensor, optical coating, structural ceramic,electrical circuit varistor, biocompatible material for bone implants, spacer material formagnetic spin valve systems, and more. Therefore, the ability to control the architectureof titanium dioxide down to nanoscale dimensions can be expected to positively impact avariety of economically important technologies. In this paper, we reported severalsynthesis methods of some typical titanium dioxide nanostructure and their opticalproperties.（1） TiO₂ nanotubes could be synthesized by hydrolysis of tetrabutyl titanate （TBT） onthe surface of carbon nanofibers （CNFs） via in situ sol-gel process, followed by removalof CNFs. In the synthesis of TiO₂ nanotubes, CNFs acted as templates. Energy-dispersiveX-ray analysis pattern （EDXA） together with the X-Ray diffraction （XRD） data furtherindicated that the as-prepared nanotubes are composed of anatase and rutile TiO₂. Studiesusing transmission electron microscopy （TEM） and field-emission scanning electron microscopy （FE-SEM） show that as-prepared product are curly and coiled nanotubes withuneven sizes.（2） In a typical synthesis, a certain amount of anatase nano-TiO₂ powder was addedinto 100 ml deionized water to form a suspension. At the same time a proper amount ofanionic surfactant was added to keep the stability of this suspension. After apre-dispersion in an ultrasonator for 30 min, the suspension was mixed into a given massof crylic-acid latex paint to get the final anatase nano-TiO₂ modified inner wall latex painthaving an anatase content of 0.7％.Anatase nano-TiO₂ modified inner wall latex paint has an active region for ultravioletlight with a range ofλ＜380 nm, while the quantity of the radiation from fluorescent lampssurface equals 0.2 mW/cm², so photocatalysis can happen even in a bright ambience viausing this special latex paint.（3） Rutile titanium dioxide microspheres with diameters of about 2-5μm have beensynthesized by a facile hydrothermal method. In a typical synthesis, 5 ml of TiCl₃solution （20％） and 2 g of FeCl₂·4H₂O were dissolved in 25 ml of distilled H₂O. Then themixture was transferred into a 50 ml Teflon-lined autoclave after 2 minutes vigorousstirring, sealed and maintained at 180℃for 24 h, then allowed to cool to the roomtemperature naturally. The precipitate was collected and washed with distilled water andanhydrous alcohol for several times, and finally dried in vacuum at 80℃for 5 h. Theinfluence of formation of TiO₂ microspheres has been investigated.