应用化学 ›› 2021, Vol. 38 ›› Issue (1): 0-0.

• 封面图片 •    下一篇

不同尺寸ZIF-8对U(VI)的吸附性能

田龙1,4, 豆维新2*, 杨玮婷2*, 王成1,3*   

  1. 1中国科学院长春应用化学研究所,稀土资源利用国家重点实验室,长春 130022
    2海南大学理学院,热带岛屿资源先进材料教育部重点实验室,海口 570228
    3天津理工大学新能源材料与低碳技术研究院,天津 300384
    4中国科学院大学,北京 100049
  • 收稿日期:2020-09-24 修回日期:2020-10-07 出版日期:2021-01-01 发布日期:2021-02-01
  • 通讯作者: *E-mail:1648214326@qq.com; wyang@icems.kyoto-u.ac.jp; cwang@tjut.edu.cn
  • 基金资助:
    国家重点研发计划(No.2017YFA0700104)、国家自然科学基金(No.21571170)和天津市自然科学基金(No.17JCZDJC000)资助

Size Effect of ZIF-8 on the Adsorption of Uranium

TIAN Long1,4, DOU Wei-Xin2*, YANG Wei-Ting2*, WANG Cheng1,3*   

  1. 1State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China;
    2Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, School of Science, Hainan University, Haikou 570228, China;
    3Institute for New Energy Materials & Low-Carbon, Technologies Tianjin University of Technology, Tianjin, 300384, China;
    4University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-09-24 Revised:2020-10-07 Published:2021-01-01 Online:2021-02-01
  • Supported by:
    National Key Research and Development Project (No.2017YFA0700104), the National Natural Science Foundation of China (No.21571170) and the Natural Science Foundation of Tianjin (No.17JCZDJC000)

摘要: 以经典的金属有机骨架(MOFs)材料ZIF-8为吸附剂,研究尺寸效应对铀吸附性能的影响。 通过3种方法合成不同粒径的ZIF-8,利用扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)、表面积与孔隙度分析仪等对其进行了表征,测试了相同条件下不同尺寸的ZIF-8对硝酸铀酰溶液中U(VI)吸附,分别对其吸附过程的动力学和吸附等温线进行了考察,并测试了材料的可重复利用性。 结果表明,成功制备了高结晶性、高纯度的ZIF-8,产物形貌呈菱形十二面体,颗粒均匀,粒径分别为约50 nm、150 nm及2 μm;3种ZIF-8具有单一均匀的微孔结构和与粒径高度相关的比表面积;不同尺寸的ZIF-8均能快速吸附溶液中的U(VI),在室温pH=3下,在70 min左右时即可吸附初始质量浓度为200 mg/L的U(VI)溶液中90%以上U(VI);其中较小尺寸(约50 nm)的ZIF-8吸附性能最好,单位质量ZIF-8吸附U(VI)的饱和吸附量达到520.26 mg/g;ZIF-8对U的吸附动力学上符合二级动力学方程,吸附等温线符合Langmuir模型,说明ZIF-8对U(VI)的捕获属于化学单层吸附;经过4个吸附-解吸循环后,3种尺寸的ZIF-8均依然保持了70%以上的去除率。

关键词: 尺寸效应, 纳米结构, ZIF-8, 铀吸附

Abstract: ZIF-8, a classical metal-organic frameworks (MOFs) material, was used as an adsorbent to study the effect of particle size on its uranium adsorption performance. ZIF-8 particles with different sizes were synthesized by three methods, and characterized by scanning electron microscope (SEM), X-ray powder diffraction (XRD), surface area and porosity analyzer. The adsorption of ZIF-8 particles with different sizes for U(VI) from uranyl nitrate solution was tested under the same conditions. The parameters of adsorption isotherm and kinetics were calculated. The results show that ZIF-8 with high crystallinity and high purity is successfully prepared. The morphology of the product is rhombic dodecahedron, and the sizes of the particles are about 50 nm, 150 nm and 2 μm with narrow distributions. The three samples have single uniform micropore structures and their BET surface areas are highly related to the particle size. All the ZIF-8 particles with different sizes can quickly adsorb 90% of U(VI) from the initial concentration of 200 mg/L of U(VI) solution in 70 min (at room temperature, pH=3).The particles with smaller size (about 50 nm) show better adsorption performance, and the saturated adsorption capacity reaches 520.26 mg/g. The adsorption kinetics conforms to the second order kinetic equation, and the adsorption isotherm conforms to the Langmuir model, which indicate that the adsorption for U(VI) of ZIF-8 belongs to chemical monolayer adsorption. After 4 cycles of adsorption and desorption, their removal rates for U(VI) are still above 70%.

Key words: Size effect, ZIF-8, Nanostructures, Uranium adsorption

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