摘要
通过多步生长及刻蚀的策略构筑了不同壳层空心结构的金属-有机框架材料(MOFs),研究了实心MIL-101、单层空心MIL-101(SSHM)、双层空心MIL-101(DSHM)和三层空心MIL-101(TSHM)对水体中抗生素的吸附行为.吸附数据表明壳层数的增加有利于土霉素和四环素吸附,其中三层空心MIL-101对土霉素和四环素的吸附量分别达到76和95 mg/g,吸附效率达到76%和48%,达到实心材料3倍吸附效率.循环测试表明TSHM对水体中抗生素吸附效率比较稳定,经过4次吸脱附后仍然具有良好的结晶性和形貌稳定性.研究表明MOFs中暴露更多的活性位点和多壳层结构有利于提高客体分子的吸附和存储,对多壳层MOFs材料拓展吸附应用方面具有指导意义.
Antibiotics have been widely used in the prevention and treatment of diseases such as humans,poultry and aquaculture due to their remarkable antibacterial effects.Nowadays,the infections caused by antibiotic-resistant bacteria are increasing,and resistance to antibiotics is probably the major public health problem.Therefore,the effective removal of trace antibiotic technology and materials in water has gradually attracted the attention of all parties in recent years.However,due to the difficulty in pore size,porosity,physical and chemical properties modification,the application of traditional porous materials,such as activated carbon,zeolites and silicates,are limited to some extent.As a new type of porous materials,metal-organic frameworks(MOFs)are considered as a promising platform for the adsorption applications.Inspired by the favorable structure and morphology of inorganic materials,hollow structures are promising materials for enhancing the adsorption performance.Herein,we fabricated multi-shelled hollow MOFs through step-by-step crystal growth and subsequent etched by acetic acid.The solid MOFs particles size about 200 nm,and the hollow cavity of single shell hollow MOFs(SSHM)about 100 nm.The diameters of double shell hollow MOFs(DSHM)inner cavity and outer shell were 50 and 50 nm,respectively.Triple shell hollow MOFs(TSHM)inner cavity and outer shell diameters were 20 and 70 nm,respectively.Powder X-ray diffraction(XRD)and N2 sorption confirmed the crystallographic structure and porosity of the resulting hollow MOFs.The hollow MOFs showed similar diffraction peaks position and intensity with pristine MOFs,which indicated that the high phase purity of the product MOFs.The BET surface of solid,single,double and triple shell MOFs were 2389.1,2454.2,2052.7 and 2396.2 m^2/g,respectively.The hollow structured MOFs exhibited higher adsorption capacity than the solid MOFs,and the adsorption capacity increased with the number of layers.Particularly,the triple-shelled hollow MOFs(TSHM)for oxytetracycline and tetracyclines adsorption capacity is about 76 and 95 mg/g,respectively,which is three times higher than the solid MIL-101.The high adsorption capacity and removal efficiency may be attributed to the enhanced active site in each layer of multi hollow structure that can sorption more molecules.The recycling experiment showed that the adsorption efficiency of antibiotics in water by TSHM was relatively stable,and it still showed good crystallinity and morphological stability after reuses of up to 4 cycles.The enhanced adsorption capacity and excellent reusability obtained in this study demonstrated the potential of multi-shelled hollow MOFs structures as a novel adsorbent for the removal of organic molecules.
作者
张浩
沈宇
田丹碧
霍峰蔚
Hao Zhang;Yu Shen;Danbi Tian;Fengwei Huo(School of Chemistry and Molecular Engineering,Nanjing Tech University,Nanjing 211816,China;Instiute of Advanced Materials(LAM),Nanjing Tech University,Nanjing 211816,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2019年第34期3632-3639,共8页
Chinese Science Bulletin
基金
科学技术部纳米重点专项(2017YFA0207201)
国家自然科学基金(21574065)资助
关键词
金属-有机框架材料
多壳层空心结构
抗生素吸附
土霉素
四环素
metal-organic framework
multi-shelled hollow materials
antibiotics adsorption
oxytetracycline
tetracyclines
