Synthesis and characterization of a new nanomagnetic coordination composite from Fe3O4 and Cu(II) complex: as an efficient catalyst in oxidation of benzyl alcohol

Abstract

New nanomagnetic coordination compound, Cu(salal)@DA@ Fe3O4, was synthesized by bonding between the Cu(II) complex and Fe3O4 nanoparticles. The Cu complex has two aldehyde groups. The surface of Fe3O4 nanoparticles was modified by the dopamine molecules and the amine group of dopamine is free. Therefore, the Cu complex is covalently anchored to Fe3O4 nanoparticle by the formation of imine bonds between the aldehyde and amine groups. On the other hand, a Cu-Schiff base complex is immobilized on nano-Fe3O4 by dopamine as a bridge. Consequently, the homogeneous Cu complex is easily converted to the heterogeneous-magnetic compound in this project. The Cu complex, Fe3O4 and new nanocomposite were characterized by general techniques such as FTIR, TGA, XRD, FESEM, MAP and EDS. The average crystallite size of Fe3O4 and Cu(salal)@DA@ Fe3O4 were calculated by Scherrer’s formula and they are 18.52 and 24.69 nm, respectively. These results indicated the average crystallite size of Fe3O4 nanomaterials is slightly increased by surface modification by Cu complex. The FESEM images show a tiny spherical mushroom morphology for both nanocompounds, and the EDS analysis confirms the presence of Fe, Cu, C and O in the nanomagnetic coordination composite. The catalytic properties of these compounds were studied and compared to oxidation of benzyl alcohol by 30% H2O2 at room temperature. The results show that the catalytic properties Cu complex and Fe3O4 were enhanced by cooperation of both compounds in a nanocoordination composite.