High-performance supercapacitor based on reduced graphene oxide decorated with europium oxide nanoparticles

Many technologies benefit from the advantages induced to graphene oxide through its loading with nano-structured species. Among these areas are the rapidly growing areas of catalysis, as well as sensing and energy storage devices. The focus of this work is on the synthesis of Eu₂O₃ nanoparticles (EuNs) by means of a facile sonochemical procedure and anchoring them onto the surface of reduced graphene oxide (RGO), through self-assembly thereof. Further, the supercapacitive characteristics of the products were evaluated through testing electrodes made of the prepared materials. The studies were conducted through cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy and the results proved that EuNs decorated RGO (EuN–RGO) have a specific capacitance (SC) of 313 F g⁻¹ in a 3.0 M KCl electrolyte, at 2 mV s⁻¹; and also 268 F g⁻¹ under a current density of 2 Ag⁻¹ based on the galvanostatic charge–discharge evaluations. The properties offered by the EuN–RGO samples could be the result of the synergy between the considerable charge mobility of the inorganic ingredient and the flexibility of the RGO sheets. The EuN–RGO further showed a high cycling durability of 96.5% of the original SC value after 4000 cycles.