Synthesis and application of core–shell magnetic metal–organic framework composites Fe3O4/IRMOF-3

A new type of magnetic core–shell structured MOF composite (Fe3O4/IRMOF-3) was successfully prepared by a facile mixed solvothermal method. Fe3O4 nanoparticles and polyvinylpyrrolidone (PVP) are the magnetic core and promoter, respectively. Fe3O4 nanoparticles are encapsulated completely inside the MOF matrix. PVP not only functions as the stabilizer to make the Fe3O4 nanoparticles well dispersed but also provides the ability to adsorb IRMOF-3 precursors onto the surface of the Fe3O4 nanoparticles. The composite possesses high crystallinity, porosity characteristics, a rapid magnetic response and good stability. In addition, the catalytic performance of Fe3O4/IRMOF-3 is investigated via the Knoevenagel condensation reaction of benzaldehyde and ethyl cyanoacetate. The conversion of ethyl cyanoacetate reaches 98.3% after 4 hours. More importantly, the catalyst can be quickly separated by a magnet and reused many times.