Cobalt and nickel ferrites based graphene nanocomposites for electrochemical hydrogen evolution

Highlights: • CoFe₂O₄/Graphene and NiFe₂O₄/Graphene were synthesized by a simple solvothermal method. • Hydrogen evolution reaction activities of CoFe₂O₄/Graphene and NiFe₂O₄/Graphene nanocomposites shows a high current density. • Enhanced current density due to low onset potential on nanocomposite surface. Cobalt and Nickel ferrite based graphene nanocomposites with increased electrochemical performances were successfully prepared by solvothermal process. To know the structure and morphology of the as-synthesized nanocomposite, the material was investigated by X-ray diffraction and electron microscopy techniques. Further, the material was tested for hydrogen production through electrochemical route. HER activity of nanocomposites was tested for hydrogen evolution at an applied potential of −1.2 to 0.8 V in acidic electrolyte. It shows good exchange current density of 47.9 mAcm⁻² and 41.2 mAcm⁻² at over potential of 248.3 mV and 259 mV and a Tafel slope of 116.6 mVdec⁻¹ and 121.4 mVdec⁻¹ for CFG and NFG nanocomposite respectively. The experimental results revealed that cobalt and nickel ferrites based graphene nanocomposites is a good electrocatalyst towards hydrogen production.