磁性纳米CoFe_2O_4/TiO_2复合材料的制备及光催化性能

Preparation and Photocatalytic Activity of Magnetic-Nanometer CoFe_2O_4/TiO_2 Composite Materials

首先用化学共沉淀法以聚乙二醇作表面活性剂制备出乙醇基CoFe2O4磁流体,再以其为前驱体、钛酸正四丁酯为原料,用溶胶-凝胶法得到易于磁分离回收的磁载光催化剂CoFe2O4/TiO2,并利用电子透射电镜(TEM),X射线衍射仪(XRD),傅立叶红外光谱仪(FTIR),振动样品磁强计(VSM),可见光分光光度计(UV-vis)等进行表征.以光催化降解甲基橙溶液为模型反应,表征其光催化活性.结果表明:钛酸正四丁酯与纳米CoFe2O4粒子表面的聚乙二醇分子发生吸附、交联,使TiO2均匀地包裹在CoFe2O4上,形成CoFe2O4/TiO2核壳结构.煅烧后获得尖晶石型CoFe2O4与锐钛矿型TiO2复合光催化粒子,其磁性能和光催化性能均较高,甲基橙降解率达90%以上.

Ethanol-based magnetic fluids were prepared firstly by a co-precipitation method with PEG as surfactant. Using ethanol-based magnetic fluids as precursors and tetrabutyl titanate as raw material, a magnetite photocatalyst CoFe2O4/TiO2 was successfully prepared by a sol-gel method： The sample was characterized by transmission electron microscopy （TEM）, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, vibrating sample magnetometer （VSM） and ultraviolet-visible spectrophotometer （UV-vis）, respectively. The photocatalytic activity was characterized using the model reaction of photo-catalytic degradation of methyl orange. The results show that the PEG-6000 molecules on the surface of CoFe2 04 nanoparticles adsorbed and cross-linked the tetrabutyl titanate molecules, the TiO2 is uniformLy coated on the surface of CoFe2O4 nanoparticles, and then core-shell nanoparticles were formed. After being calcined, the spinel CoFe2O4 and anatase TiO2 composite nanoparticles were obtained, whose magnetism and photocatalytic activity were high. The degradation proportion of methyl orange is higher than 90%.