ZrxCo0.8−xNi0.2−xFe2O4-graphene nanocomposite for enhanced structural, dielectric and visible light photocatalytic applications

Zirconium doped nickel cobalt ferrite (ZrxCo0.8−xNi0.2−xFe2O4) nanoparticles and ZrxCo0.8−xNi0.2−xFe2O4-graphene nanocomposites were synthesized by a cheap and facile co-precipitation method. Annealing was done at 750 °C for 6.5 h. Spinel cubic structure of prepared nanoparticles was confirmed by X-ray powder diffraction (XRD) technique. Crystalline size of nanoparticles was observed in the range of 18–27 nm. Graphene was synthesized by Hummer's method. Formation of rGO was confirmed by UV-visible spectroscopy (UV-vis) and XRD. ZrxCo0.8−xNi0.2−xFe2O4-graphene nanocomposites were prepared by ultra-sonication route. Grain size of nanoparticles and dispersion of nanoparticles between rGO layers was determined by Scanning electron microscopy (SEM). In application studies of nanoparticles and their nanocomposites, photocatalytic efficiency of nanoparticles under visible light irradiation was observed by degradation of methylene blue. Charge transfer resistance was measured by electrochemical impedance spectroscopy (EIS) and the variation in dc electrical resistivity was analyzed by room temperature current voltage characteristics (I-V). Dielectric constant was also evaluated in frequency range from 1 MHz to 3 GHz. All these investigations confirmed the possible utilization of these materials for a variety of applications such as visible light photocatalysis, high frequency devices fabrication etc.