改性M-MOF-74(M=Ni、Co)对亚甲基蓝的吸附性能研究

Adsorption properties of M-MOF-74(M=Ni,Co)for methylene blue

合成了两种金属有机骨架材料M-MOF-74(M=Ni、Co),并在不同温度下进行煅烧改性,用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、热重分析(TGA)和氮气吸附脱附法对合成的材料进行表征。以亚甲基蓝为污染物模板分子,研究MOF-74基材料对有机污染物的吸附性能,探究实验条件如改性温度、吸附剂种类、吸附剂用量和吸附时间的影响。结果表明:400℃煅烧后,材料(标记为M-400)孔径变大,对亚甲基蓝有优异的吸附能力,可在30 min内快速达到平衡,吸附过程符合Langmuir吸附模型,准二级动力学模型可以很好的拟合M-400吸附去除亚甲基蓝,Ni-400对亚甲基蓝最大吸附量为165.29 mg·g^(-1),Co-400对亚甲基蓝最大吸附量为271.74 mg·g^(-1)。

Two kinds of M-MOF-74(M=Ni,Co)materials were synthesized and modified by calcination at different temperatures.X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscope analysis(SEM),thermogravimetric analysis(TGA)and nitrogen adsorption-desorption methods were applied to characterize the obtained materials.The adsorption performance of MOF-74-based materials was studied using methylene blue as a pollution template molecule.The effects of the calcination temperatures,the types of adsorbents,the amounts of adsorbents and the adsorption time were investigated in detail.The results show that the pore sizes of the modified materials(M-400)become larger after calcination at 400℃,and M-400 displays excellent adsorption capacity for methylene blue.The adsorption of methylene blue on M-400 quickly reaches the equilibrium within 30 min,and the adsorption process is in agreement with the quasi-second-order kinetic model and the Langmuir isotherm equation.The maximum adsorption amount of methylene blue in Ni-400 and Co-400 is 165.29 mg·g^(-1) and 271.74 mg·g^(-1),respectively.