Optimizing the physical properties of cobalt/graphene nanocomposites for technological applications

Cobalt nanoferrites with formula CoFe2O4, and CoFe2O4/GR were synthesized using a citrate auto-combustion method. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy (SEM) and the Fourier-transform infrared (FTIR) spectroscopy. The dependence of structure, magnetic and optical properties of cobalt/graphene nanocomposites on the graphene content was studied. The obtained data show that the CoFe2O4 nanoparticles are homogenously decorated on the graphene layers, which act as magnetically inactive layers in turn affecting the magnetization. The high coercivity Hc values reflect that CoFe2O4/GR nanocomposites are hard magnets at room temperature. The energy band gap of the cobalt/graphene is estimated using Kubelka–Munk equation. The energy gap of the investigated nanocomposites was found about 1.4 eV for direct transition. The samples with high saturation magnetization values can affect by the external magnetic field, which is favorable to their application in high adsorption capacity.