Research On Photocatalytic Properties Nonmetal And Rare Earth Doped TiO₂

Titanium dioxide is a great photocatalytic material. It has good application prospect. It has manyadvantages such as high photocatalytic activity, chemical stability, non-toxic and low cost. But, its practicalapplication is limited in the UV region because of its large band gap value of3.2eV and low quantumyields, so TiO₂can only capture about3-5%of the solar irradiance at the earth’s surface. Therefore, inorder to improve the photocatalytic activity of TiO₂, this paper carried out research work including thefollowing several aspects. The main contents are the following:1, In order to find a method which is more simple and environmental for the preparation of titaniumdioxide material, three different kinds of preparation methods are used. They are sol-gel method, inversemicroemulsion method and biological template method. The prepared catalysts were characterized byX-ray diffraction, scanning electron microscope, and UV–Vis spectra.The photocatalytic activity of thethree different samples was evaluated through the photodegradation of Rhodamine B under UV light. Andthen the best method was found.2, In order to improve the photocatalytic activity of TiO₂, boron doped TiO₂and phosphorus dopedTiO₂nanoparticles were prepared using a sol–gel method. By contrast, boron doped TiO₂has smallercrystallite size and higher photocatalytic activity than that of phosphorus doped TiO₂samples and undopedTiO₂. And then different dosage of boron doping TiO₂were prepared, The photocatalytic activity of thesamples was evaluated by the photodegradation of Rhodamine B, and then research the relation aboutphotocatalytic performance and calcined temperature, boron doping amounts, PH, the quantity of catalystFinaly the best boron doping condition was found.3, In order to further research the modification effect on doping TiO₂, Gadolinium–boron codoped andmono-doped TiO₂nanoparticles were prepared using a sol–gel method, and tested for photocatalyticactivity by the UV light after a further calcination process. For comparison, a pure TiO₂sample was alsoprepared and tested under the same conditions. The prepared catalysts were characterized by X-raydiffraction, scanning electron microscope, and UV–Vis spectra. The photocatalytic activity of the samples was evaluated through the photodegradation of three different dyes under UV light. The experimentsdemonstrated that the gadolinium–boron codoped TiO₂（Gd–B–TiO₂） sample calcined at500℃possessedthe best photocatalytic activity, and the photodegradation rate of the Reactive Brilliant Red K2G aqueoussolution could reach to95.7%under UV irradiation for80min. The results showed that Gd–B–TiO₂hassmaller crystallite size and higher photocatalytic activity than that of mono-doped TiO₂samples andundoped TiO₂.