磷钼钨杂多酸修饰金属有机骨架MOF-5复合材料吸附亚甲基蓝

采用水热合成法,在合成金属有机骨架MOF-5的过程中引入活性组分磷钼钨杂多酸(H₆P₂Mo₁₅W₃O₆₂),制备出一种新型吸附剂H₆P₂Mo₁₅W₃O₆₂/MOF-5。 利用H₆P₂Mo₁₅W₃O₆₂/MOF-5材料对亚甲基蓝溶液进行了材料的吸附性能研究,探讨了亚甲基蓝溶液的初始pH值和初始浓度以及不同吸附温度对吸附量的影响。 结果表明,在较低的温度和亚甲基蓝溶液较低的初始pH值的条件下,有利于H₆P₂Mo₁₅W₃O₆₂/MOF-5对亚甲基蓝的吸附。 实验结果能够较好地符合Langmuir吸附等温式以及二级动力学模型,对亚甲基蓝的最大吸附量可达401.6 mg/g。 热力学参数ΔG<0、ΔH<0和ΔS>0,表明H₆P₂Mo₁₅W₃O₆₂/MOF-5对亚甲基蓝的吸附过程是自发、放热的。 此外,还探讨了H₆P₂Mo₁₅W₃O₆₂/MOF-5对甲基紫、孔雀石绿、罗丹明B和甲基橙等其它染料的吸附性能,结果表明,H₆P₂Mo₁₅W₃O₆₂/MOF-5对阳离子染料有较好的吸附效果。

Adsorption of Methylene Blue by Phosphomolybdiumtungstic Acid Decorated Metal Organic Framework MOF-5

The novel absorbent H₆P₂Mo₁₅W₃O₆₂/MOF-5 was prepared by the hydrothermal synthesis method. The active component H₆P₂Mo₁₅W₃O₆₂ was introduced during the synthesis of metal organic framework MOF-5. The adsorption property of the composites on methylene blue from water solution was investigated, and the effects of the experimental parameters including the temperature, the initial pH value and initial concentration of methylene blue solution were discussed. The results demonstrate that the lower temperature and lower initial pH value are more favorable for the adsorption methylene blue onto H₆P₂Mo₁₅W₃O₆₂/MOF-5. The experiment data can be well described in the Langmuir equation and a pseudo-second-order kinetic model, and the maximum adsorption capacity of methylene blue is 401.6 mg/g. Thermodynamic parameters ΔG<0, ΔH<0 and ΔS>0 reveal that the adsorption process is spontaneous and exothermic. Furthermore, we also explored the adsorption properties of H₆P₂ Mo₁₅W₃O₆₂/MOF-5 to methyl violet, malachite green, rhodamine B, methyl orange and other dyes. The results indicate that this new absorbent shows better adsorption performance towards cationic dyes.