Fe3O4@HTlc的制备及其对甲基橙的吸附研究

采用液相非稳态共沉淀法制备了磁性镁铝类水滑石(Fe3O4@HTlc)，采用透射电子显微镜、粉末X射线衍射仪、傅里叶变换红外光谱仪、振动样品磁强计、比表面分析仪、微电泳仪等对样品的形貌和结构进行了表征，并比较了 Fe3O4@HTlc和HTlc对甲基橙的吸附性能。结果表明，Fe3O4@HTlc为顺磁性、具有核-壳结构和较大比表面积、带有正电荷的近球状颗粒。甲基橙在Fe3O4@HTlc和HTlc上的吸附动力学曲线均符合准一级动力学方程；吸附等温线均符合Langmuir吸附等温式；298 K时Fe3O4@HTlc和HTlc对甲基橙的饱和吸附量分别为138.89和147.06 mg/g，但Fe3O4@HTlc对甲基橙有较强吸附推动力和较短的吸附平衡时间。二者对甲基橙的吸附量均随温度的升高和pH (5~11)的增加而降低。

Preparation of Fe3O4@Hydrotalcite-like Compound and Its Adsorption Capacity for Methyl Orange

Mg-Al hydrotalcite-like compound (HTlc) and Fe3O4@HTlc were prepared by coprecipitation method. The phase identification and morphology of the HTlc and Fe3O4@HTlc were characterized by TEM, XRD, FTIR, VSM, N2 adsorption-desorption, and microiontophoresis apparatus. The adsorption performance of Fe3O4@HTlc and HTlc toward methyl orange was compared. Results showed that Fe3O4@HTlc particles iswere a near spherical particles with paramagnetism, core-shell structures, larger specific surface areas and positive charges. The adsorption kinetics and adsorption isotherms of Fe3O4@HTlc and HTlc can be well described by the pseudo-first order kinetic and Langmuir isotherm. The saturated?adsorption quantity of Fe3O4@HTlc and HTlc toward methyl orange arewere 138.89 and 147.06 mg/g, respectively, butand Fe3O4@HTlc hasd a strong driving force toward methyl orange and a shorter adsorption equilibrium time. The adsorption amounts of methyl orange on both Fe3O4@HTlc and HTlc decreased gradually with increasing temperature and increasing initial pH in the range of 5-11.