Coating of Carbon Black (CB) and Graphene Oxides (GOs) with Magnetite (Fe3O4)

Composites containing iron oxides are obtained by the co-precipitation of iron(II) and iron(III) compounds in the presence of different substrates in an alkaline environment. Newly synthesized graphene oxide (GO), reduced graphene oxide (rCO) and carbon black (CB) are used as substrates. Methods of obtaining GO–amorphous iron compound, rGO–Fe3O4, and CB–Fe3O4 composites are developed. It is determined that rGO–Fe3O4 and CB–Fe3O4 magnetic composites can be obtained at 70–75°C, while in the presence of GO, a non-magnetic composite containing an amorphous iron compound is formed under the same conditions. This composite, when heated in vacuum at 170–175°C, undergoes exfoliation, in result of which a powder composite rGO–amorphous iron compound is formed, the volume of which is 2.7 times greater than that of initial powder. Partial reduction of the formed composite takes place at 550°C and rGO–Fe3O4 is obtained. Formation of the magnetite phase is determined by XRD (X-Ray Diffraction) analysis. The structural-morphological study of the synthesized composites is carried out by the SEM (Scanning Electron Microscopy) method. Their magnetic characteristics are studied using VSM (Vibrating Sample Magnetometry) method.