磁性负载型光催化材料TiO2／Fe3O4的制备、改性及表征

Preparation,Modification and Characterization of Titania-Coated Magnetic Photocatalyst TiO_2/Fe_3O_4

采用溶胶-凝胶法制备核-壳式结构的TiO2/Fe3O4负载型光催化剂,并对其进行中间层改性,制备出TiO2/SiO2/Fe3O4光催化材料.研究了pH等制备条件对TiO2/Fe3O4材料光催化性能的影响,并对比了改性前后降解甲基橙的光催化性能,通过X射线衍射仪(XRD)、红外光谱仪(FT-IR)、振动样品磁强计(VSM)和透射电子显微镜(TEM)对改性前后颗粒的磁性能、晶相和形貌进行了表征.研究表明:磁性负载光催化剂TiO2/Fe3O4和TiO2/SiO2/Fe3O4均为超顺磁性,且光催化性能较高,在1 h内甲基橙脱色率达90%以上,其降解反应均属于一级动力学反应;SiO2中间层的引入可显著提高材料的饱和磁化强度、光催化速率和循环使用的光催化活性.

Core-shell photocatalyst TiO2/Fe3O4 particles were prepared by sol-gel technique. Intermediate SiO2 was then added to form the catalyst TiO2/SiO2/Fe3O4. The photocatalytie activities of the catalysts were investigated by changing the preparation conditions such as pH and the ratio of Fe3O4 and TiO2. The magnetic properties, crystal phase and morphology of the particles were characterized by XRD, FT-IR, VSM and TEM. The result showed that both TiO2/Fe3O4 and TiO2/SiO2/Fe3O4 photocatalyst had superparamagnetic property and relatively high photocatalytic activity. Deeolourization rates of methyl-orange were up to 90% in 1 h and the photocatalytic degradation of TiO2/Fe3O4 and TiO2/SiO2/Fe3O4 belonged to first order kinetic reactions. The introduction of SiO2 layer had a significant effect on improving saturated magnetization, photoeatalytic rate and recycling photocatalytic activity.