Enhanced electrochemical performance of MnNi 2 O 4 /rGO nanocomposite as pseudocapacitor electrode material and methanol electro-oxidation catalyst

Abstract Binary transition metal oxides with encouraging electrocatalyst properties have been suggested as electrode materials for supercapacitors and methanol oxidation. Hence, in this work, a binary mixed metal oxide based on nickel and manganese (MnNi 2 O 4 ) and its hybrid with reduced graphene oxide were synthesized by a one-step hydrothermal method. After physical and morphological characterization, the potential of these nanostructures was investigated for use as supercapacitor electrodes and methanol electro-oxidation. The results of the electrochemical analysis showed a substantial effect of adding rGO to the MnNi 2 O 4 . The MnNi 2 O 4 /rGO hybrid electrode supercapacitor exhibited good stability of 93% after 2000 consecutive CV cycles and a specific capacitance of 575 F g −1 at the current density of 0.5 A g −1 . Furthermore, the application of this hybrid nanomaterial in the methanol electro-oxidation reaction (MOR) indicated its appropriate electrochemical efficiency and stability in methanol oxidation. Our results show that MnNi 2 O 4 /rGO can be considered as a promising electrode material for energy applications.