Preparation of three-layer magnetic composite Fe3O4@poly acry lic acid@ZiF-8 for efficient removal of malachite green in water
A magnetic composite material(Fe3O4@PAA@ZIF-8)was designed and synthesized with magnetic nanoparticles as the nucleus,polymer as the intermediate layer,and zeolitic imidazolate framework-8(ZIF-8)as the outer layer.First,Fe3O4 nanoparticles were prepared by solvothermal method,and then polyacrylic acid(PAA)layer was coated on the surface of Fe3O4 nanoparticles by distillation precipitation polymerization,and finally ZIF-8 was coated on the surface of the Fe3O4@PAA by in-situ deposition method(composite method).Based on the character-ization of the composition,structure and morphology of Fe3O4@PAA@ZIF-8,the adsorption properties of malachite green(MG)were studied in depth.Transmission electron microscope(TEM)showed that Fe3O4@PAA@ZIF-8 had a distinct three-layer structure,with an average particle size of 117 nm for Fe3O4,a thickness of about 17 nm for the PAA layer,and a thickness of about 14 nm for the ZIF-8 layer.The adsorption capacity of Fe3O4@PAA@ZIF-8 for MG increased with the increase of pH,and the adsorption process conformed to the quasi-second-order kinetic mod-el and the Langmuir isothermal model,and the maximum adsorption capacity could reach 9 759 mg·g-1.In addition,Fe3O4@PAA@ZIF-8 had good reusability,and the maximum adsorption capacity of MG(500 mg·L-1)could still reach 982 mg·g-1 after 8 cycles.
Fe3O4zeolitic imidazolate framework-8adsorptionmalachite green
万方数据
