Electrospinning Synthesis of ZIF-67/PAN Fibrous Membrane with High-capacity Adsorption for Malachite Green

Metal-organic frameworks (MOFs) exhibit great potential for dye adsorption. However, MOF powder is difficult to remove from aqueous solution, which hinders the practical application of MOFs. Integration of MOFs on polymeric fibrous membrane provides a new strategy to reach the achievements that not only keep the adsorption ability of MOFs for dyes, but also easily remove the MOF/dye complex from water. Here, we successfully synthesize zeolitic imidazole framework-67/polyacrylonitrile (ZIF-67/PAN) fibrous membrane with ZIF-67 loading ratio of 54 % by electrospinning method. The average diameters of ZIF-67 nanoparticles and ZIF-67/PAN fibers are about 200 nm and 0.72 mu m, respectively. The adsorption process of MG on ZIF-67 nanoparticles or ZIF-67/PAN fibers followed a pseudo-second-order kinetic model and fitted Langmuir isotherm. The maximum adsorption capacities of ZIF-67 nanoparticles and ZIF-67/PAN fibers are 2545 and 1305 mgg(-1), respectively. After four regeneration cycles, the ZIF-67/PAN fibers membrane still exhibit over 92 % of the original capacity of ZIF-67/PAN fibers. In addition, ZIF-67/PAN fibers also show good adsorption abilities for Congo red (849 mgg(-1)) and Basic fuschin (730 mgg(-1)). Therefore, ZIF-67/PAN fibers would be as a promising adsorbent for the removal of dye in industrial application because of its simple preparation method, excellent adsorption property, ease of separation and favorable reusability.