Preparation and Photocatalytic Activities of TiO2/MCM-41 Photocatalyst
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摘要: 用溶胶-凝胶法制备了不同TiO2含量的TiO2/MCM-41光催化剂,以罗丹明B为模拟有机污染物,对催化剂的光催化脱色性能进行了考察。用XRD、UV-Vis漫反射、N2吸附等方法对光催化剂进行了表征,结果表明:TiO2/MCM-41的比表面积和孔体积随TiO2含量的增加而减小,TiO2/MCM-41负载型催化剂上TiO2平均晶粒尺寸比纯TiO2的小。20%TiO2/MCM-41的光生电子-空穴分离效应最高,且光催化脱色活性最高。光催化反应体系中h+是主要的活性自由基,TiO2/MCM-41的光催化活性由材料的吸附能力和所含TiO2的光催化性能共同决定。Abstract: TiO2/MCM-41 photocatalysts with different titania content were prepared by loading titania onto the mesopores of MCM-41 molecular sieves via a sol- gel method. The photocatalytic activities of TiO2/MCM-41 photocatalysts were evaluated by the photocatalytic degradation of Rhodamine B aqueous solution.TiO2/MCM-41 photocatalysts were characterized by X-ray diffraction (XRD),UV- Vis diffuse reflectance spectroscopy and N2 adsorption techniques. The results indicate that both the BET surface area and pore volume of TiO2/MCM-41 photocatalyst decrease with the increase in content of loaded titania. The average crystal size of titania loaded on TiO2/MCM-41 is smaller than that of pure titania nanoparticles. 20% TiO2/MCM-41 photocatalyst has the highest photo- induced charge separation efficiency. Among all the photocatalysts,the 20% TiO2/MCM-41 sample possesses the best photocatalytic activity. The h+ is main active species during the photocatalytic process. The photocatalytic activities of the TiO2/MCM-41 photocatalyst depend on their adsorption abilities and the activity of titania loaded onto the MCM-41 molecular sieves.
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Key words:
- titania /
- MCM-41 /
- photocatalytic decolorization /
- radicals
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