Synthesis Of Magnetic Zeolite And Metal Organic Framework Materials And Application To The Adsorption Of Metal Ions

Zeolite and metal organic framework are considered as porous material and have been paid more and more attention duo to their large specific surface area, structural diversity, adjustable channel, and functional surface. They have been widely used in gas adsorption, catalysis, and biological medicine. In addition, they can also be used as adsorbent and applied to the adsorption of metal ions. However, tedious steps such as centrifuging and washing are often necessary in conventional adsorption procedures. CoFe2O4 and Fe3O4 are two kinds of ferrite material with advantages of low price, biocompatibility, and environment-friendliness. They have been used as magnetic adsorbent. In this paper, we took advantages of magnetic material and porous materials(zeolite and metal organic framework) and prepared magnetic composite adsorbents. The adsorbents were applied to the adsorption of metal ions. The detailed items are as followings:(1) Magnetic cobalt ferrite(CoFe2O4)-coated zeolite was prepared with a solvothermal method via FeCl3·6H2O, CoCl2·6H2O and ethylene glycol. The obtained CoFe2O4-zeolite was characterized with X-ray diffraction, X-ray photoelectric spectroscopy, Fourier-transformed infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer to determine its crystal structure, morphology, and magnetic properties. Then the magnetic zeolite was used as adsorbent for the adsorption of Ga ions and In ions-combined with flame atomic absorption spectroscopy. Effects of experimental parameters, including adsorption time and temperature, were discussed. Experimental data were studied by employing various isotherm models, such as Langmuir and Freundlich models. Furthermore, thermodynamic, kinetic functions, and the reusability of the adsorbent was investigated.(2) Fe3O4 was manufactured by a solvothermal method and silanization by tetrabutyl orthosilicate. Then polyvinyl pyrrolidone was employed to modify the surface of Fe3O4. AlCl3·6H2O and 2-aminaterephthalic acid were added to obtain Fe3O4@NH2-MIL-53(Al). The crystal structure, functional groups, and magnetic properties of the material were characterized by means of X-ray diffraction, Fourier transform infrared spectrometry, and vibrating sample magnetometer. Then the metal organic framework was used as adsorbent and the adsorption of lead was investigated by combining with flame atomic absorption spectroscopy. Experimental conditions affecting the adsorption percentage were discussed and experimental operation parameters were optimized. Adsorption isotherm, kinetics, and thermodynamics studies were conducted. In addition, the reusability of Fe3O4@NH2-MIL-53(Al) was studied.