Fabrication Of Functionalized TiO₂Nanoparticles And Their Photocatalytic Application

Titanium dioxide （TiO₂） is widely concerned in photocatalytic applicationbecause of its chemieal stability, high catalytic efficiency, nontoxicity, and low cost.However, the practical application of TiO₂is retarded by its wide band gap, highrecombination rate of the photogenerated electron-hole pairs, poor adsorbability tomost of organic contaminants, and poor recovery. In this work, some TiO₂compositeswere prepared by in-situ sol-gel method to extend the absorption of TiO₂to the visiblespectrum region, improve the separation effeciecy of photogenerated carriers, achievethe recycle, enhance the adsorptivity to organic pollutants, and increasephotocatalytic efficiency. The main research contents are listed below:（1） Fabrication and photocatalystic application of TiO₂/Ag-RG: TiO₂/Agcomposite was prepared through sol-gel method, and then the composite wasassembled with graphene oxide to get TiO₂/Ag-RG. Compared to commercial P25,both of the resulted photocatalysts showed stronger absorption in visible spectrumregion and exhibited higher photocatalytic degradation efficiency of MB.（2） Fabrication and characterization of magnetic TiO₂hybird nanopaticles: fourkinds of magnetic TiO₂hybird nanopaticles （MT@TiO₂, MT@SiO₂@TiO₂, MT@TiO₂-RG and MT@SiO₂@TiO₂-RG） were designed and facilely produced bycombining sol-gel and assembling processes. Compared with P25, all the four kinds ofmagnetic TiO₂hybird nanopaticles exhibit much stronger light absorption in thevisible region. Furthermore, all of the four kinds of magnetic TiO₂hybird nanopaticlescould be rapidly recoveried by magnetic separation.（3） Adsorption and photocatalytic property of magnetic TiO₂hybirdnanocatalystes: compared with P25, the magnetic TiO₂-RG hybird nanocatalysts（MT@TiO₂-RG and MT@SiO₂@TiO₂-RG） exhibited much bigger adsorptioncapacities of2,4-D, and all the resulted catalysts obtained excellent photoctalyticdegradation efficiencies of2,4-D. Especially, MT@SiO₂@TiO₂-RG got to almost100%degradation efficiecy of2,4-D, and furthmore showed excellent photocatalyticperformance in real application.