The Preparation Of TiO₂ Supported On Glass Fiber With High Photocatalytic Activity

The ways to deal with environmental contamination has become a serious issue for human being and thus more and more scholars are making effort on study of pollutant solution.As one kind of photocatalyst, TiO₂ （nanomaterials）has a vast range of prospects for wasted-water treatment,gas purification and hydrogen preparation,thus lots of attention has aroused.But the TiO₂ nanoparticles suspension,which is widely studied now,has many disadvantages:it is easily to flocculate and deactivate,difficult to be recovered,,the efffiency of using photoenergy is low,therefore the practical application of this photocatalysis is restricted.In recent years, scholars mode great effort for TiO₂ loading and TiO₂ doping technology to solve the existing problems,also gain a lot of significant results.In this paper, TiO₂ loading and TiO₂ doping technology were synthesized,to seek suitable doping elements, proportions and preparation process.1、Firstly, butyl titanate was used as precursor , using glass fiber as a carrier, the Supported photocatalyst （TiO₂/GF）were prepared by Sol-Gel method in this paper.The samples was characterized by X-ray diffraction spectra（XRD）、thermogravimetric differential scanning calorimeter （TG- DSC）、scanning electron microscope （SEM）.The influences of heat treatment temperature on the structure and morphology of the product was investigated. The optimum calcination treatment temperature is 550℃, at this temperature,the morphology of the product is uniform,the crystallite is complete. The titania dioxide gradually transformed into rutile crystal phase with the increasing of the calcination temperatures,and due to thermal stress and volatile organic compounds,the TiO₂ film is tend to burst.When the heat treatment temperature reaches 550℃,flake TiO₂ stability supported on the surface of GF.2、The Si-doped nano-TiO₂ supported on glass fiber（Si-TiO₂/GF） was prepared by tetraethyl orthosilicate（TEOS） as a Si source. The effect of doping Si and doping ratio onTiO₂ grain and light absorption was studied. The results show that doping Si has the function as below, restraining the transformation of TiO₂ from anatase to rutile, preventing the growth and aggregation of TiO₂ grain whose grain size was diminished from 13.8nm to 10.3nm when doped by Si, and meanwhile effectively improving the visible light absorption of the photocatalyst.3、The Ag-doped nano-TiO₂ supported on glass fiber （Ag-TiO₂/GF） was prepared by photochemical deposition. The effect of AgNO₃ concentration on the deposition of Ag and the influence of doping Ag on TiO₂ crystal form and photocatalysis were researched. The results show that as the AgNO₃ concentration increased, the deposition of Ag presents a rising trend and it would remain a proportion of 2%（mole ratio of Ag/Ti） when AgNO₃ concentration is no less than 0.1mol/L. Analyzed by XRD and XPS, it shows that Ag could exist in form of simple substance which enables the mean size of TiO₂ grain diminished from 40nm to 31nm and alters the band structure of TiO₂, causing obvious red shift of samples thereby to largely improve its property of photocatalysis against visible light.