Absorption of Iodide Ions in Aqueous Solution by ZIF-67 and ZIF-8

Two zeolite-like imidazate metal-framework materials ZIF-67 and ZIF-8 were synthesized by using Co(NO_(3))2,Zn(NO_(3))_(2),2-methyl imidazole and methanol as raw materials,and these two materials were used to adsorb iodine ions in water.The impact of pH,contact time and temperature etc.on the adsorption capability of iodide ions in aqueous solutions by the two ZIF materials was investigated.The results show that the optimal adsorption pH was 7,and the optimal adsorption time was 18 h.The adsorption of iodide ions by ZIF-67 was consistent with the Langmuir adsorption isotherm,while the absorption of iodide ions by ZIF-8 was in better consistency with the Freundlich adsorption isotherm.The maximum adsorption capacity of iodide ions by ZIF-67 and ZIF-8 was 141.81 and 474.02 mg/g respectively.The adsorption of iodide ions by the two materials was more in line with the quasi-first-order kinetic model,and the adsorption was monolayer adsorption.