Synthesis, characterization and electrochemical performance of graphene decorated with 1D NiMoO4·nH2O nanorods

Abstract

One-dimensional NiMoO₄·nH₂O nanorods and their graphene based hybrid composite with good electrochemical properties have been synthesized by a cost effective hydrothermal procedure. The formation of the mixed metal oxide and the composite was confirmed by XRD, XPS and Raman analyses. The morphological characterizations were carried out using FESEM and TEM analyses. The materials were subjected to electrochemical characterization through cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) studies with 6 M KOH as the supporting electrolyte. For NiMoO₄·nH₂O, a maximum specific capacitance of 161 F g⁻¹ was obtained at 5 A g⁻¹ current density, accompanied with an energy density of 4.53 W h kg⁻¹ at a steady power delivery rate of 1125 W kg⁻¹. The high utility of the pseudocapacitive NiMoO₄·nH₂O was achieved in its graphene based composite, which exhibited a high specific capacitance of 367 F g⁻¹ at 5 A g⁻¹ current density and a high energy density of 10.32 W h kg⁻¹ at a power density of 1125 W kg⁻¹ accompanied with long term cyclic stability.