Preparation And Photocatalytic Properties Of Metal Doped TiO₂ Mesoporous Materials

With the rapid development of social economy,the global environmental pollution becomes more and more serious.At present,due to the people’s attention on the micro organic pollution of drinking water and the volatile organic compounds of air et al,the photocatalytic technology with the potential application value became a hot topic in the field of environmental protection,chemical synthesis and new materials,et al.Titanium dioxide,dut to its unique optical,electrical and physical properties,excellent chemical stability,non–toxicity,and inexpensiveness,is an ideal photocatalyst.However,the utilization rate to the sun light rate is very low,and the recombination rate of photogenerated electron hole pair is extremely large.On the other hand,the available commercial catalysts tend to have a low specific surface area.Thus,the catalyst has a relatively low photocatalytic activity.Therefore,to improve the photocatalytic activity of titanium dioxide became one hot topic in the field of photocatalysis materials.By the method of ion doping to titanium dioxide.The mesoporous W–TiO₂,Zn–TiO₂ and Ce–TiO₂ composite photocatalytic materials were prepared successfully by using sol–gel method.In this experiment,tetrabutyl titanate was used as the titanium source.Ammonium wolframate,zinc acetate dihydrate and cerium nitrate hexahydrate were used as the tungsten,zinc and cerium sources,respectively.Hexadecyl trimethyl ammonium bromide or polyethylene glycol were used as the template agents.Acetylacetone was used as the hydrolyzation inhibiter,The mixture of absolute ethyl alcohol and deionized water was used as the main solvent.The crystal structure,surface morphology and photocatalysis of the prepared composite photocatalytic materials were analyzed by X–ray diffraction,scanning electron microscopy,transmission electron microscopy and photocatalytic degradation,et al.The experimental results showed that the samples have a good photocatalytic performance.The average diameter of the mesoporous W–TiO₂ composites is between 8.02 nm and 9.20 nm.When the W:Ti=3:100,The degradation rate to methylene blue of the W–TiO₂ composites to methylene blue,corresponding to the W and Ti molar ratio 3:100,showed the best photocatalytic ability,and the degradation rate to methylene blue of the samples reached up to 99.2%.The average diameter of the mesoporous Zn–TiO₂ composite is between 7.71 nm and 8.93 nm.The degradation rate of the Zn–TiO₂ composite to methylene blue,corresponding to the Zn and Ti molar ratio 3:10,showed the best photocatalytic ability,and the degradation rate to methylene blue of the samples reached up to 89.9%.The average diameter of the mesoporous Ce–TiO₂ composite is between 6.88 nm and 6.95 nm.The degradation rate of the Ce–TiO₂ composite to methylene blue,corresponding to the Ce and Ti molar ratio 4:10,showed the best photocatalytic ability,and the degradation rate to methylene blue of the samples reached up to 91.4%.