Robust Nanocomposite of Nitrogen-Doped Reduced Graphene Oxide and MnO₂ Nanorods\nfor High-Performance Supercapacitors and Nonenzymatic Peroxide Sensors

Abstract

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