Cost-effective synthesis of rGO/CeNiO3 perovskite nanocomposites for enhanced and stable supercapacitors and oxygen evolution reaction catalysts†

The main goal of this study is to make a nanocomposite electrode and electrocatalyst that combines the high conductivity of reduced rGO with CeNiO₃ nanoparticles to improve the OER and supercapacitors’ performance. This nanocomposite, rGO/CeNiO₃, was designed to improve energy storage capacity and catalytic efficiency. To synthesize the rGO/CeNiO₃ nanocomposite, reduced graphene oxide was produced using a straightforward hammer modification method with a milling process, while cerium perovskite nanoparticles and composites were obtained through coprecipitation and ultrasonication techniques. The produced nanoparticle's shape, oxidation states, and crystal structure were all determined by the many characterizations that were carried out. The electrochemical performance tests compared the behavior of CeO₂, CeNiO₃, and rGO/CeNiO₃ electrodes to evaluate their potential in supercapacitors. The rGO/CeNiO₃ nanocomposite exhibited impressive pseudocapacitive properties, with a specific capacitance of 1208.7 F g⁻¹ at a current density of 1 A g⁻¹. The material's cycling stability was remarkable; it maintained 91% of its initial capacitance even after 6000 charge discharge. Additionally, the rGO/CeNiO₃ composite exhibited superior and consistent electrocatalytic performance. To reach a current density of 10 mA cm⁻² during the oxygen evolution process, an overpotential of just 227 mV was needed. These results suggest that graphene and perovskite-based nanocomposites have significant potential for supercapacitors and reliable electrocatalysts.