Hydrothermal synthesis of iron oxide grown on nickel foam for supercapacitors

Metal oxides with nanostructures and nickel foam (NF) are evaluated as highly promising electrode materials for supercapacitors, though their performance is required for practical applications. In this study, we synthesized iron oxide nanoparticles from iron nitrate nonahydrate onto NF via a hydrothermal process at a low temperature of 120 °C for a short duration of 6 h. The performance was significantly influenced by optimizing the mass ratio of iron nitrate nonahydrate (0.25, 0.5, and 1 mmol) in terms of charge storage capability, surface area, impedance behavior, and energy density. The optimal loading of 0.5 mmol of iron nitrate nonahydrate on NF-based supercapacitors achieved a specific capacitance of 191.4 F g⁻¹ with an energy density of 17.1 Wh Kg⁻¹ at 1 A g⁻¹. The relatively simple synthesis process and excellent performance of the iron oxide on NF composite highlights its potential as an electrode material for next-generation symmetric supercapacitors.