中文摘要：

以微米级Fe3O4作为载体，用一种改进的溶胶一凝胶法制得TiO2／SiO2／Fe3O4包覆型光催化剂。采用振动样品磁强计（VSM）、X射线衍射仪（XRD）和透射电镜（TEM）分别对该催化剂的磁性能、晶体结构和微观形貌进行了表征，并通过对Cr^6＋水溶液的光催化还原对其催化活性进行了测试。结果表明，TiO2／SiO2／Fe3O4是由中间层SiO2和外壳TiO2组成的双层包覆粒子，通过与未包覆SiO2粒子TiO2／Fe3O4的比较，可知采用此种溶胶一凝胶过程制得的TiO2／SiO2／Fe3O4具有较好的磁性能和较高的光催化还原活性。

英文摘要：

Using micron-sized Fe3O4 as supporter, TiO2/SiO2/Fe3O4 coated particles were prepared by an improved sol-gel process, Their magnetic property, phase structure and morphology were characterized by means of VSM, XRD, and TEM, The photocatalytic activity of TiO2/SiO2/Fe3O4 was investigated by the photoreduction of Cr^6＋ aqueous solution. The results indicated that the TiO2/SiO2/Fe3O4 two-coated particles were composed of SiO2 mesosphere and TiO2 crust, and the thus prepared TiO2/SiO2/Fe3O4 showed better magnetic properties and higher photocatalytic activity than TiO2/Fe3O4 without SiO2 coating.