锰锌铁氧体/SiO_2复合磁性材料的制备和表征

Preparation and Characterization of Composite Magnetic Material Mn-Zn Ferrite/SiO_2

以正硅酸乙酯(TEOS)作为包覆材料,对锰锌铁氧体纳米颗粒进行SiO2包覆,制备出锰锌铁氧体/SiO_2复合磁性材料。利用FTIR,XRD,SEM等技术对其进行了表征,并研究了其对模拟亚甲基蓝废水的吸附脱色效果。实验结果表明:当SiO_2质量分数为40%1时,采用先将锰锌铁氧体在柠檬酸溶液中搅拌分散3 h后,加人氨水调节溶液pH,再继续搅拌分散3 h的分段分散方法制备的复合磁性材料对亚甲基蓝废水的处理效果更好,处理亚甲基蓝质量浓度为50 mg/L、COD为160 mg/L的废水,废水脱色率为97.2%,COD去除率为19.3%。表征结果显示:复合磁性材料锰锌铁氧体/SiO_2为球形颗粒,平均粒径为100 nm;SiO_2包覆前后锰锌铁氧体的晶型均为尖晶石型结构,在复合磁性材料中SiO_2以无定型的形态存在。

The composite magnetic material Mn-Zn ferrite/SiO2 was prepared by coating Mn-Zn ferrite magnetic nanoparticle with SiO2 using tetraethoxysilane （TEOS） as precursor. The composite magnetic material was characterized by FTIR, XRD and SEM, and its adsorption effects on decolorization of the simulated methylene blue wastewater were studied. The experimental results show that： The composite magnetic material has a good treatment effect when it is prepared under the conditions of SiO2 mass fraction 40 % and the staged dispersion method of stirring Mn-Zn ferrite in citrate acid solution for 3 h, controlling pH with ammonia, and then stirring for 3 h; When the methylene blue mass concentration and COD of the wastewater are 50 mg/L and 160 mg/L, the decolorization rate and COD removal rate are 97.2% and 19.3%, respectively. The characterization results indicate that： Mn-Zn ferrite/SiO2 is spherical particle with 100 nm of the average diameter; The crystal types of the bare and SiO2-coated Mn-Zn ferrite are both spinel phase and SiO2 in the composite magnetic material is amorphous.