H_6P_2Mo_(18)O_(62)/Zn(BDC)(Bipy)_(0.5)复合材料的合成、表征及对亚甲基蓝的吸附

在溶剂热条件下,以H6P2Mo18O62、对苯二甲酸(H2BDC)、4,4'-联吡啶(Bipy)和硝酸锌为原料构筑了1个三维金属有机骨架复合材料H_6P_2Mo_(18)O_(62)/Zn(BDC)(Bipy)_(0.5),并采用红外光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、热重分析(TG)、N2吸附-脱附等手段对产物进行了表征.同时,研究了产物对水溶液中亚甲基蓝(MB)的吸附性能,并探讨了MB初始p H值、初始浓度和温度对吸附量的影响.结果表明,产物的等温吸附模型符合Langmuir等温吸附模型,动力学符合拟二级动力学.H_6P_2Mo_(18)O_(62)/Zn(BDC)(Bipy)_(0.5)对亚甲基蓝的吸附是自发和放热的,此外,产物对甲基紫、罗丹明B、孔雀石绿等阳离子染料也具有良好的吸附性能.

Synthesis and Characterization of Composite H6 P2 Mo18 O62/Zn(BDC) (Bipy) 0. 5 and Its Adsorption Activity for Methylene Blue

By employing the H6P2Mo18O62, terephthalic acid(H2BDC), 4,4'-bipyridine(Bipy) to assemble with Zn2+ ion, a three-dimensional ( 3D ) metal organic framework composite, named H6 P2 Mo18 O62/Zn( BDC) ( Bipy) 0. 5 , was synthesized. The composition, structure, morphology, stability and toleration of H6P2Mo18O62/Zn(BDC)(Bipy)0.5 were characterized by X-ray powder diffraction pattern(XRD), Fourier transform infrared(FTIR) spectrum, scanning electron microscopy(SEM), thermogravimetric(TG) analysis and N2 adsorption-desorption analysis. The adsorption of methylene blue ( MB ) onto H6 P2 Mo18 O62/Zn( BDC) ( Bipy) 0. 5 in aqueous solution was studied. The effects of the experimental parameters including the temperature, the initial pH value and initial concentration of methylene blue solution were discussed. The ex-perimental data could be well described by the Langmuir equations and pseudo-second-order kinetic model. The adsorption process of methylene blue on the composite was spontaneous and exothermic. Furthermore, we also explored the adsorption properties of H6 P2 Mo18 O62/Zn( BDC) ( Bipy) 0. 5 to methyl violet, malachite green, rhodamine B, and methyl orange. The results indicated that this new absorbent showed better adsorption per-formance towards cationic dyes.