纳米γ-氧化铁的制备及其吸附性能研究

Preparation of γ-Fe2O3 nanoparticles and its adsorption properties

以硝酸铁和十二烷基三甲基溴化铵为原料,采用固相法制备了γ-氧化铁纳米粒子。通过X射线衍射、氮气吸附-脱附、磁性测试等手段对γ-氧化铁样品进行了表征。研究了γ-氧化铁对有机染料直接耐酸大红4BS的吸附性能。结果表明,制备的γ-氧化铁样品为γ-氧化铁纳米粒子,平均晶粒尺寸为18.5nm;γ-氧化铁的比表面积为83.2m^2/g,孔容为0.25cm^3/g,最可几孔径为3.8nm,属于介孔范围;γ-氧化铁的最大饱和磁化强度为63.7A·m2/kg;介孔γ-氧化铁对直接耐酸大红4BS的吸附过程符合准二级吸附动力学模型;γ-氧化铁对直接耐酸大红4BS的吸附符合Langmuir吸附等温式,极限吸附量为113.3mg/g;将γ-氧化铁脱附处理后可重复使用。

γ-Fe2O3 nanoparticles were prepared by a solid phase method using ferric nitrate[Fe(NO3)3·9H2O] and dodecyl trimethylammonium bromide(DTAB) as raw materials.The sample was characterized by X-ray diffraction(XRD),N2 adsorption-desorption(BET) and vibrating-sample magnetometer(VSM),and its adsorption ability for direct acid-resistant red 4BS was also studied.The results showed that the prepared γ-Fe2O3 sample was γ-Fe2O3 nanoparticles with an average crystallite size of 18.5 nm,a specific surface area of 83.2 m^2/g,the pore volume was 0.25 cm^3/g and the most probable pore size was 3.8 nm which belonged to the mesoporous range.The maximum saturation magnetization(Ms) of γ-Fe2O3 was 63.7 A·m2/kg. The adsorption process of mesoporous γ-Fe2O3 on direct acid-resistant red 4BS conformed to the quasi-secondary adsorption kinetics model.The adsorption process of γ-Fe2O3 on direct acid-resistant red 4BS also fitted well with Langmuir isotherm model and its maximum adsorption capacity was estimated to be 113.3 mg/g,and the γ-Fe2O3 nanoparticles could be reusable.