磁性CaFe2O4纳米材料的制备及吸附性能研究

Preparation and adsorption performance of magnetic calcium ferrite nanoparticle

采用溶胶凝胶法制备了磁性铁氧体CaFe2O4,并采用比表面积分析仪、X射线粉末衍射仪和振动样品磁强计对其进行表征。实验考察了阴阳离子等因素对吸附刚果红效率的影响。在最佳实验条件下,CaFe2O4对刚果红的吸附率可达96%以上,CaFe2O4对刚果红的吸附符合准二级反应动力学(r>0.999),CaFe2O4表面的活性吸附位点密度比较高。在288K、298K和323K温度下,吸附过程更符合Langmuir模型,饱和吸附量分别为41.580、40.933和38.565mg·g^-1,该吸附过程是放热的物理过程。吸附剂再生实验表明吸附刚果红之后的CaFe2O4可采用磷酸盐/乙醇溶液洗脱解析处理,重复利用五次后,吸附率仍可达到95%以上,说明CaFe2O4具有良好的回收再利用性能。

CaFe2O4 was prepared by sol-gel method,The characterization of CaFe2O4 was determined by Brunauer-Emmett-Teller(BET),X-ray diffraction,vibrating sample magnetometer(VSM)and transmission electron microscopy(TEM).The effects of various parameters such as coexisting ions on the adsorption of congo red were investigated.The results showed that the adsorption efficiency of congo red could reach 96%at the optimum conditions,adsorption kinetic results showed that pseudo-second-order model could be to describe well the experimental data(r>0.999),The density of active adsorption sites on the surface of CaFe2O4 was relatively high.The sorption data could be well interpreted by the Langmuir model of congo red on CaFe2O4 with 288K、298K and 323K.The maximum adsorption capacity were 41.580,40.933 and 38.565 mg·g^-1,the adsorption process was a physical process and exothermic process.The adsorbent regeneration experiments showed that the phosphate/ethanol elution could be used to treat the CaFe2O4 adsorbed congo red.The adsorption percentage of CaFe2O4 for congo red could reach 95%after five regeneration-removal cycles,confirming a good reuse performance of the CaFe2O4.