Research On Photocatalysis Of Rare Earth Ions-doping TiO₂ And Titanate

As a result of the development of global industrial advancement, the environmental pollution question is more and more serious. The environment protection and the sustainable development became the most important question that people must consider. But using the semiconducting materials in particular nanometer level ones has aroused the world widespread interest to the environment in at the obvious degradation effect to pollutant. The perovskite compound is a kind of new Functional Materials, which has outstanding performance and widespread versatility use. It can form various composite oxides if its A or B position is replaced by other metal ion. Ion flaws appear which improve compound'photocatalysis nature and made crystal structure no basic difference.The thesis studied nanophase materials with their photocatalysis character and mechanics. TiO₂ was obtained by Sol-gel method and perovskite type nanophase materials were got by LCS method. And TiO₂ was modified by alloying PEG and doping rare earth ion. It analysed the relation between photocatalysis character and technological parameter. The main test contents were as follows:TiO₂ was modified by La³⁺, La³⁺-Ce³⁺å’ŒFe³⁺-Ce³⁺ doping with sol-gel method. Its surface topography and grain size and photocatalysis performance were studied. Test got the relation between degradation rate and the best doping amount.It studied the influence that polyethylene glycol (PEG) addition amount to photochemical catalysis of TiO₂. Mineralization rate was finded with COD method. Studies showed that there was a best value and degradation rate increased more than before.Three perovskite type compounds such as PbTiO₃,SrTiO₃ and Bi₄Ti₃O₁₂ were obtained with LCS method. Characters were studied by differential analysis and XRD. It compared performance with appearance by the low temperature combustion method and the Sol-gel method. The former degradation and grain were better than Sol-gel method. Photocatalysis capacity of three materials was compared, it showed that Bi₄Ti₃O₁₂ was the best and SrTiO₃ was the worst.Bi4Ti3012 films were got by sol-gel method. The degradation of Al³⁺/Bi₄Ti₃O₁₂ was higher than Er³⁺-Ni2+ and Bi₄Ti₃O₁₂/TiO₂ films.In a word, paper got some conclusions at preparation technology,photocatalysis mechanics,rare earth ion doping amount and the degradation rate through TiO₂ and several kinds of perovskite compound research. The results had some innovation, and at the same time laid the foundation for the further study.