表面包覆TiO2材料的制备及光催化降解染料废水

Preparation of Nano Titania Supported on Mesoporous SBA-15 and Photocatalytic Activity of Dye Wastewater

以介孔硅基分子筛SBA-15为载体,采用溶胶-凝胶法在SBA-15分子筛表面包覆TiO_2。制备了不同TiO_2含量的链状二维六方形介孔复合材料。采用电子显微镜扫描仪、X射线衍射仪、傅立叶红外光谱、紫外-固体漫反射等技术对复合材料进行表征。SEM结果表明样品具有良好的包覆效果,UV-Vis光谱结果表明样品具有较好的光吸收能力。XRD结果表明复合材料表面包覆的TiO_2为锐钛矿和金红石的混合晶型,随载体用量的增加TiO_2的粒径逐渐减小。以光催化降解亚甲基蓝为目标,研究复合材料在煅烧温度、载体用量、底物溶液初始浓度等影响因素下的光催化效果。考察复合材料的再生光催化活性。研究表明:介孔TiO_2复合材料相比于市售P-25有较高的光催化活性。复合材料可进行回收利用,并且其介孔结构牢固不易崩塌。

With mesoporous silica SBA-15 as a carrier of catalyst, sol-gel method was used to clad SBA-15 with hydrolytic tetrabutyl titanate. The composites of different titania contents had 2D hexagon mesoporous structure, and the composites with various titania contents were prepared and characterized by X-ray diffraction （XRD）, scanning electron microscope techniques （SEM）, Fourier transform infrared spectroscopy and diffusive reflective UV-Vis spectroscopy. SEM results showed that nano titania has been equably supported on mesoporous SBA-15. UV-Vis spectrum indicated that the sample has good absorption ability. XRD results showed that titania phase is a mixed crystal of anatase and rutile. The addition of mesoporous SBA-15 can prevent the crystal grain from growing. The photocatalytic activities of TiO2/SBA-15 were evaluated by photocatalyfic degradation of methylene blue, and photocatalysis effect of compound materials by various calcining temperature, carrier amount and substrate solution concentration factors was studied. Photocatalytic activity of the recycling composite materials was discussed. Experimental results showed that the photocatalytic activity of compound materials was higher than P-25 pure titania nanoparticles. The composiies can be reused and its mesoporous structure was not easy to collapse.