Nanoengineered reduced graphene oxide-Fe doped α-MnO2: A multifunctional smart material for energy storage and environmental remediation

Nanocomposites based on alpha-MnO2, reduced graphene oxide (rGO)-based alpha-MnO2, and Fe-doped alpha-MnO2 were successfully synthesized via the hydrothermal method. These materials were investigated for their potential applications in supercapacitors and photocatalytic dye degradation. This investigation involves a phase transition from alpha-MnO2 to the cubic phase of alpha-MnO2, as revealed by X-ray diffraction (XRD) analysis. The electrochemical performance and photocatalytic activity were significantly enhanced through the incorporation of rGO and Fe doping into the alpha-MnO2 lattice. Notably, the rGO-based 5 % Fe-doped MnO2 (referred to as GFMO5) sample exhibits a high specific capacitance of 683.35 F/g(-1), attributed to its mixed phase and defective morphology. Moreover, the introduction of Fe into the MnO2 structure led to a phase transition, as confirmed by XRD, FE-SEM, and XPS results. This phase transition resulted in the remarkable degradation of methylene blue (MB) dye, achieving up to 90 % degradation under visible light irradiation. This research underscores the potential of these nanocomposite materials for advanced energy storage and environmental remediation applications.