类蛋结构的可磁分离光催化剂纳米球的制备及催化性能

Preparation and Photocatalytic Properties of Magnetically Separable Photocatalyst Nanospheres with Egg-like Structure

通过反胶束和静电自组装方法制备了一种类蛋结构的可磁分离光催化剂纳米材料SiO2@NiFe2O4@TiO2(TSN),这种光催化剂对甲基橙废水有较好的降解效果,并显示出了超顺磁性,通过外加磁场方便地实现催化剂在水中的分离与回收.该光催化剂纳米球的X射线衍射、TEM和FTIR结果表明,铁酸镍纳米粒子被包裹在SiO2内,形成SiO2@NiFe2O4(SN)纳米球载体,纳米TiO2颗粒组装在SN表面,形成TiO2光催化壳层.利用甲基橙的降解考察了光催化剂纳米球的活性,结果表明,在NiFe2O4和TiO2之间包覆一层无定形的SiO2可以显著提高光催化剂纳米球TSN的催化活性.

A novel magnetically separable photocatalyst nanosphere TiO2@SiO2@NiFe2O4（TSN） with egg-like structure was prepared by reverse micelles method and electrostatic self-assembly method.The photocatalyst shows high photocatalytic activity for the degradation of methyl orange in water.The magnetic property measurements indicate that the photocatalyst possesses a superparamagnetic nature,which can be separated and recycled conveniently through an external magnetic field.X-ray diffractometer（XRD） and transmission electron microscope（TEM） were used to characterize the structure of the TSN photocatalyst nanosphere.The results indicate that nickel ferrite core nanoparticles are completely encapsulated into silica nanospheres as carrier,and titania nanoparticles are assembled onto the surface of SN nanospheres,forming a TiO2 shell for photocatalysis.The SiO2 layer between the NiFe2O4 core and the TiO2 shell effectively prevents the injection of charges from TiO2 particles to NiFe2O4,which gives rise to an increase in photocatalytic activity.