磁性纳米TiO2/SiO2/Fe3O4光催化剂的制备及光催化性能研究

以化学共沉淀法制备的纳米铁氧体Fe₃O₄ 为磁载体，采用溶胶-凝胶法制备易于固液分离回收的新型磁性纳米TiO₂/SiO₂/Fe₃O₄ 光催化剂。采用X射线衍射、透射电镜、扫描电镜、傅立叶红外变换光谱和紫外可见漫反射光谱等对催化剂进行表征。以酸性大红3R为目标降解物，对催化剂的光催化性能进行了研究。结果表明，磁性纳米TiO₂/SiO₂/Fe₃O₄ 光催化剂样品混晶中，锐钛矿相TiO₂ 占90%以上，制备的催化剂样品为层状结构，平均颗粒粒径约为(50~80) nm，呈现顺磁性，在外加磁场的作用下，催化剂可与液相迅速分离。同时，磁性纳米TiO₂/SiO₂/Fe₃O₄ 光催化剂具有较强的光催化活性，在光催化剂用量0.5 g·L^-1 、溶液初始浓度100 mg·L^-1 和光催化反应120 min条件下，酸性大红3R降解率达95%。

Preparation and photocatalytic properties of magnetic nanoszied TiO2/SiO2/Fe3O4 photocatalyst

A magnetic nanosized TiO2/SiO2/Fe3O4 photocatalyst was prepared by sol-gel method, using nanosized magnetite matrix Fe3O4 prepared by chemical co-precipitation as the magnetic core, and was characterized by XRD, TEM, SEM, FT-IR and UV-Vis DRS. Photocatalytic activity of the TiO2/SiO2/ Fe3O4 was tested for degradation of acidic scarlet 3R. The results showed that there existed over 90% anatase in crystalline phase of the TiO/SiO/Fe3O4, with layered structure and grain diameter of about （50 - 80） nm. The catalyst was of good paramagnetism, which made it easily separable from liquid. The TiO2/SiO2/Fe3O4 photocatalyst exhibited higher photocatalytic activity , with photocatalytic degradation rate for acid scarlet 3R of up to 95% under catalyst dosage of 0.5 g · L^-1 , acidic scarlet 3R concentration of 100 mg· L^-1 and reaction time of 120 min.