In the present study, a novel core-shell structured CoFe2O4/MCM-41 composite was prepared through modification of MCM-41 (Mobil Composition of Matter) nanoparticles with 3,4,5-tri hydroxyphenyl acetic acid (HA) followed by treatment with Ag (I) particles. The prepared material was denoted as CF/MC/HA/A with CF (CoFe2O4), MC (MCM-41), HA (3,4,5-tri hydroxyphenyl acetic acid), and A (Ag (I) and characterized using highresolution transmission electron microscopies (HRTEM), field emission scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), vibrating-sample magnetometer (VSM) and nitrogen adsorption desorption isotherm. Results showed that the magnetite nanoparticles were coated with the MCM-41 silica with the formation of core-shell structured materials. In this approach, the CF/MC/HA/A composite with spherical particles consisted of a mesoporous structure with a surface area by BET of 230.5 m2 /g, mean pore size of 4.88 nm, and pore volume of 0.281 cm3 /g. The CF/MC/HA/A was successfully applied as a powerful catalyst for green synthesis of 5- substituted 1H-tetrazoles in water. The catalyst could be fully recovered by an external magnetic field and showed good reusability. The catalytic test showed that silver supported on the CF/MC hybrid showed much better catalytic activity than silver supported on CoFe2O4, indicating that MCM-41 plays an important role in CF/ MC hybrid for the synthesis of tetrazole.
