Robust Nanocomposite of Nitrogen-Doped Reduced Graphene Oxide and MnO₂Nanorods for High-Performance Supercapacitors and Nonenzymatic Peroxide Sensors

Abstract

The urgent demand of sustainable energy systems and reliable sensing devices has fostered the development of cost-effective, multifunctional electrode material based platforms. In this work, we have demonstrated the bifunctionality of nitrogen-doped reduced graphene oxide-MnO2 nanocomposite (NRGO-MnO2), toward two most diverse and challenging applications: (i) supercapacitor and (ii) peroxide sensor, which was synthesized by a facile one-pot hydrothermal method. The electrochemical investigations revealed its high specific capacitance (648 F g–1 at 1.5 A g–1) with remarkable rate performance (retains 80.20% up to 10 A g–1) and long-term cyclic efficiency. Additionally, it can detect peroxide rapidly (2 s), with high sensitivity (2081 μAmM–1 cm–2) and a noteworthy detection limit (24 nM) in a wide dynamic range (0.4–121.2 μM). Fascinating features such as the distinguished selectivity, repeatability, and operational stability suggests its potency to be an ideal electrode for peroxide sensors. Finally, the charge transfer kinetics and capacitive components, probed by electrochemical impedance spectroscopy (EIS), are found to be in correlation with other investigations. The positive synergism between MnO2 nanorods and NRGO induces higher conductivity and surface area, which eventually promotes superior supercapacitor and sensor performances. The results highlight NRGO-MnO2 nanocomposite as a multifunctional, cutting edge, and sustainable material for next-generation energy storage and sensing applications.