The role of reduced graphene oxide on the electrochemical activity of MFe2O4 (M = Fe, Co, Ni and Zn) nanohybrids

In this work, a comparative study of electrochemical performance of reduced graphene oxide-ferrites (RGO-MFe2O4, M = Fe, Co, Ni, and Zn) nanohybrids synthesized by hydrothermal method was done. The structural morphology and investigation of other physical properties of nanohybrids confirm the cubic spinel phase of the MFe2O4, reduction of graphene oxide and the distribution of ferrite nanoparticles (NPs) on RGO nanosheets. The role of RGO on the electrochemical behavior of nanohybrids was understood by quantifying the charge storage capacitance and charging-discharging behavior in a 0.1 M Na2SO4 electrolyte. The specific capacitance values of pristine Fe3O4, CoFe2O4, NiFe2O4, and ZnFe2O4 are 128, 117, 15.2 and 9.1 F g(-1) respectively whereas specific capacitance of RGO-Fe3O4, RGO-CoFe2O4, RGO-NiFe2O4 and RGO-ZnFe2O4 are 233, 200, 25 and 66.8 F g(-1) respectively. Our investigation suggests that apart from specific surface area of nanohybrids other factors such as structural morphology determine interaction between nanohybrids and electrolyte ions which play critical role in elevating the performance of electrodes. (C) 2017 Elsevier B.V. All rights reserved.