ZIF-8-SiO2的制备及其对U(VI)的吸附

以沸石咪唑酯骨架结构材料ZIF-8及硅酸四乙酯(TEOS)为原料制备ZIF-8-SiO₂复合材料，并采用XRD、SEM、EDS等方法对ZIF-8-SiO₂的结构及吸附U(VI)前后的形貌进行表征，结果表明ZIF-8-SiO₂成功制备且对U(VI)具有良好的吸附作用。以静态吸附实验，分别考察了pH值、时间、温度、溶液初始铀浓度、盐浓度及超高压环境等对ZIF-8-SiO₂吸附性能的影响。由实验结果可得，在初始浓度为80 mg·L?1时，25℃下ZIF-8-SiO₂对U(VI)的最大实际吸附量为498 mg·g?1，根据Langmuir模型拟合结果分析得出，ZIF-8-SiO₂对U(VI)的理论吸附量最高可达678.5 mg·g?1，且在200~500 MPa范围内，压强越高越有利于吸附。通过FTIR、XPS等方法对ZIF-8-SiO₂吸附铀酰离子前后的结构进行分析，探究该吸附过程中可能存在的吸附机制。 

ZIF-8-SiO2 and adsorption on U(VI)

Zeolite imidazole ester framework structure material ZIF-8 and TEOS were used to prepare ZIF-8-SiO₂ composite, the structure of ZIF-8-SiO₂ and the morphology before and after adsorption of U(VI) were characterized by XRD, SEM, EDS. And the results show that ZIF-8-SiO₂ is successfully prepared and has a good adsorption effect on U(VI). The effects of pH value, time, temperature, initial uranium concentration and salt concentration on the adsorption performance of ZIF-8-SiO₂ were investigated by static adsorption experiments. According to the experimental results, when the initial concentration is 80 mg·g?1, the maximum actual adsorption capacity of ZIF-8-SiO₂ on U(VI) at 25℃ is 498 mg·g?1, and according to the analysis of Langmuir model fitting results, the theoretical adsorption capacity of the material on U(VI) is up to 678.5 mg·g?1. And in the range of 200~500 MPa, the higher the pressure, the better the adsorption. FTIR and XPS were used to characterize the structure of the material before and after uranylion adsorption, to explore the possible adsorption mechanism during the adsorption process.