Abstract:

Fe₃O₄@SiO₂@TiO₂ magnetic material of core-shell structure was prepared by coprecipitation coupled solgel method, which was loaded on activated carbon(AC) to prepare a new photocatalyst Fe₃O₄@SiO₂@TiO₂-AC. The material was characterized by SEM, FTIR, XRD, VSM, and the degradation efficiency of HA in water by which was also investigated. The results indicated that, for a HA water sample with the initial mass concentration of 5 mg/L and the pH of 7, the catalytic removal rate reached 96.1% when 400 W high pressure mercury lamp was used as light source, the catalyst dosage was up to 200 mg/L and the reaction time last for 60 min. Furthermore, the photocatalytic reaction process conforms to the Langmuir-Hinshelwood kinetic model. There was a synergistic effect between Fe₃O₄@SiO₂@TiO₂ and AC, which could effectively enhance the catalytic performance of photocatalyst. The material has good catalytic stability, and the photocatalytic degradation rate of HA reaches 84.7% after the 5th cycle.

Key words: titanium dioxide, photocatalysis, magnetic materials, activated carbon, humic acid, Fe₃O₄@SiO₂@TiO₂-AC

摘要：

采用共沉淀法耦合溶胶-凝胶法制备了核壳结构的磁性颗粒Fe₃O₄@SiO₂@TiO₂，将其负载在活性炭（AC）表面，制得新型光催化剂Fe₃O₄@SiO₂@TiO₂-AC。采用SEM、FTIR、XRD、VSM对材料进行表征，并探究该催化剂对水中腐殖酸（HA）的去除效能。结果表明，以400 W高压汞灯作为光源，投加量为200 mg/L时，60 min内对初始质量浓度为5 mg/L、pH为7的含HA水样去除率可达96.1%。Fe₃O₄@SiO₂@TiO₂-AC对HA的光催化降解符合Langmuir-Hinshelwood（L-H）动力学模型。Fe₃O₄@SiO₂@TiO₂与AC存在协同作用，可有效增强复合光催化剂的催化效能。材料具有较好的催化稳定性，5次重复使用后，对水样中HA的去除率仍能达到84.7%。

关键词: 二氧化钛, 光催化, 磁性材料, 活性炭, 腐殖酸, Fe₃O₄@SiO₂@TiO₂-AC

CLC Number: 

• O643.36

• X703