Synthesis and physical properties of spinel ferrites/MWCNTs hybrids nanocomposites for energy storage and photocatalytic applications

NiFe2O4, NiFe2O4/MWCNTs, CoFe2O4 and CoFe2O4/MWCNTs nanocomposites were synthesized via the hydrothermal method. XRD, FT-IR, SEM and TEM techniques have been used to investigate the structural properties. CoFe2O4/MWCNTs has a good morphology with small sizes compared to NiFe2O4/MWCNTs. UV-vis. DRS analysis showed that the nanocomposites have high absorbance of irradiation in the whole range of the wavelengths (200-900 nm). The optical energy gaps of the nanocomposites have been calculated. Using VSM technique, NiFe2O4 and NiFe2O4/MWCNTs exhibited super-paramagnetism at room temperature, while CoFe2O4 and CoFe2O4/MWCNTs exhibited ferromagnetism with saturation magnetization of 37.8, 25.5, 66.46 and 51.49 emu/g, respectively. The AC conductivity measurements for NiFe2O4 and CoFe2O4 NPs revealed an increase in conductivity with the addition of MWCNTs as well as the dielectric measurements. The structural and electrical properties of CoFe2O4/MWCNTs make it of potential for capacitive storage and optoelectronic devices. Promising magnetic-optical properties can be utilized for developing recyclable photocatalytic applications.