机械化学法制备ZIF-8及其对铀的吸附性能研究OA

Zinc zeolite imidazole framework material(ZIF-8)is suitable for uranium adsorption due to its high specific surface area and abundant active sites.Aiming at the problems of long time and large consumption of organic solvents in the synthesis of ZIF-8 by traditional solvent method,ZIF-8 was rapidly synthesized by green and efficient mechanochemical method using zinc hydroxide and 2-methylimidazole as raw materials and used for uranium adsorption.The results show that the ZIF-8 prepared by mechanochemical method has good crystallinity,rhombic dodecahedron morphology,specific surface area of 1 642 m2/g,and rich surface defects and active sites on the surface.Under suitable conditions,the removal rate of uranium by ZIF-8 is more than 99.99％,the maximum adsorption capacity is 476 mg/g,and the adsorption can reach equilibrium within 20 min.The process is a single-layer chemical adsorption mechanism.The cost analysis results show that the synthesis efficiency of mechanochemical method is 16 times higher than that of traditional solvent method,and former's theoretical material cost per gram of uranium is only 3.5％of that of the latter.The mechanism analysis results show that the high specific surface area of the material and the synergistic effect of hydroxyl groups and imidazole nitrogen atoms are the key to the efficient adsorption of U(Ⅵ).ZIF-8 prepared by rapid mechanochemical method has good performance and has certain application potential in the field of uranium adsorption.