A comparative study of the structural, magnetic and electrochemical properties of Al3+ and Cu2+ substituted NiZn ferrite/reduced graphene oxide nanocomposites

摘要

NiZn ferrite/reduced graphene oxide (Ni(0.8)Zno(0.2)Fe(2)O(4)/rGO) nanocomposite and Al3+ and Cu2+ substituted NiZn ferrite/reduced graphene oxide (Ni0.8Zn0.2Al0.1Fe1.9O4/rGO and Ni(0.6)Cuo(0.2)Zn(0.2)Fe(2)O(4)/rGO) nanocomposites were directly synthesized by one-step hydrothermal route. XRD and FTIR confirmed the formation of Ni(0.8)Zno(0.2)Fe(2)O(4)/rGO, Ni0.8Zn0.2Al0.1Fe1.9O4/rGO and Ni(0.8)Zno(0.2)Fe(2)O(4)/rGO nanocomposites. The average crystallite size was found to be 16.9-20.4 nm. The substitution of Al3+-/Cu2+ for Fe3+ /Ni2+ ions promotes a variation in unit cell due to the difference of ionic radius between Al3+/Cu2+ and Fe3+/Ni2+, which leads the lattice parameter to vary from 8.353 angstrom to 8.394 angstrom. Magnetic measurements reveal the saturation magnetization to vary with the replacement of Al3+/Cu2+ for Fe -1-/Ni2+ ions. The variations of saturation magnetization in Al3+ and Cu2+ substituted NiZn ferrite/reduced graphene oxide nanocomposites have been explained in the light of Neel's two-sublattice theory. A maximum specific capacitance of 136.91 F/g and energy density of 16.80 W h/kg were obtained in Ni0.8Zn0.2Al0.1Fe1.9O4/rGO nanocomposite at a current density of 1 A/g. The enhanced electrochemical performances could be related to the high electronic conduction of Ni0.8Zn0.2Al0.1Fe1.9O4/rGO nanocomposite.