Sonochemical synthesis and characterization of Co3O4nanocrystals in the presence of the ionic liquid [EMIM][BF4]

For the first time, a sonochemical process has been used to synthesis cobalt oxide Co3O4nanoflowers and nanorods morphology in the presence of the ionic liquid 1-Ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] as reaction media and morphology template. Different sonication time periods and different molar ratios of the ionic liquid (IL) were used to investigate their effects on the structural, optical, chemical and magnetic properties of the produced Co3O4nanoparticles. During synthesis process brown powder contains cobalt hydroxide Co(OH)2and cobalt oxyhydroxide (Cobalt hydroxide oxide) CoO(OH) was formed, after calcination in air for 4h at 400°C a black powder of Co3O4nanoparticles was produced. The produced Co3O4nanoparticles properties were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscopy (TEM), FTIR spectroscopy, UV-vis spectroscopy, and Vibrating Sample Magnetometer (VSM). To explain the formation mechanism of Co3O4NPs some investigations were carried on the brown powder before calcination.