稀土负载钛-硅沸石ETS-10的制备及其光催化性质

摘要

The three dimensional microporous titanosilicate,ETS-l0,was synthesized by a hydrothermal synthesis route using TiC14 and a sodium silicate aqueous solution as starting materials.Lanthanide (La,Ce,Pr,Nd) loaded ETS-10 catalysts were prepared by the impregnation method.The catalysts were characterized by X-ray diffraction,29Si magic angle spinning NMR,UV-Vis diffuse reflectance spectroscopy,N2 adsorption-desorption measurement,and X-Ray fluorescence spectroscopy.The degradation of methyl orange under near-UV light was used to investigate the photocatalytic activity of the catalysts in aqueous suspensions.The lanthanide loaded ETS-10 catalysts exhibit higher activity than the unmodified ETS-10.The combination of loading lanthanide and increasing the surface defects of ETS-10 by a HF treatment gave an enhancement of the photocatalytic activity,which became comparable with that of anatase TiO2.%以水玻璃和四氯化钛为原料,在不使用有机模板剂、氟离子和晶种的条件下,用水热法合成了钛-硅沸石ETS-10,将La、Ce、Pr和Nd四种稀土元素负载到合成的ETS-10上.通过X射线粉末衍射、N2吸附-脱附、29Si魔角旋转核磁共振、紫外漫反射光谱、X射线荧光光谱等表征手段对负载前后的ETS-10进行了表征.以有机染料甲基橙为底物,考察了负载各种稀土及氢氟酸腐蚀对ETS-10的光催化活性的影响.结果表明,四种稀土元素的引入均可有效提高ETS-10的光催化活性.反应活性提高的程度与稀土元素负载量有关.对ETS-10同时进行氢氟酸腐蚀和稀土元素的负载,可以将ETS-10的光催化活性提高近一倍,与锐钛矿相TiO2相当,但前者更易分离.