磁性光催化剂Fe_3O_4/SiO_2/TiO_2的制备及光催化降解苯酚

Preparation of Fe_3O_4/SiO_2/TiO_2 magnetic photocatalyst and the photocatalytic degradation of phenol

采用撞击流-旋转填料床辅助沉淀法连续制备Fe_3O_4磁性纳米颗粒,然后采用溶胶-凝胶法制备了具有磁性核壳结构Fe_3O_4/SiO_2/TiO_2颗粒,通过傅里叶变换红外光谱(FTIR)、X射线衍射仪(XRD)、透射电子显微镜(TEM)、热重分析仪(TGA)、振动样品磁强计(VSM)和紫外-可见漫反射光谱(UV-vis)等对材料的微观结构、形貌及性能进行了表征。考察了正硅酸乙酯添加量、铁钛比对Fe_3O_4/SiO_2/TiO_2磁性催化剂催化性能的影响。结果表明:制得的Fe_3O_4/SiO_2/TiO_2结晶度好,磁响应性高。当正硅酸乙酯添加量为20mL、铁钛比为1:8时,制备的Fe_3O_4/SiO_2/TiO_2纳米光催化剂表现出较高的光催化活性和磁性能,紫外光照射2h后,苯酚水溶液降解效率高达86.7%。

Impinging stream-rotating packed bed auxiliary precipitation method was used for the continuous preparation of magnetic Fe3O4 nanoparticles,and then the Fe3O4/SiO2/TiO2 composite particles with magnetic core-shell structure were synthesized by sol-gel method.The microstructures,morphology and properties of the obtained materials were characterized by Fourier infrared spectrum(FTIR),X-ray diffraction(XRD),transmission electron microscopes(TEM),thermogravimetric analysis(TGA),vibrating sample magnetometer(VSM),ultraviolet visible light diffuse reflectance spectra(UV-vis),and some other technologies.The effects of the ferroferric-to-tetrabutyl titanate molar ratio,and the dosage of the tetraethoxysilane on the catalytic performance of Fe3O4/SiO2/TiO2 magnetic photocatalyst were investigated.The results confirmed that the well-designed photocatalyst exhibited a high crystallinity and high magnetic response.The Fe3O4/SiO2/TiO2 nano-photocatalysts with the dosage of the tetraethoxysilane of 20mL and the molar ratio of ferroferric to tetrebutyl titanate of 1∶8 exhibited the best photocatalytic activity and magnetic performance,and the phenol degradation efficiency reached 86.7%after 2 hours UV irradiation.