Fabrication of Spike-Like Spherical Iron Manganite Nanoparticles for the Augmented Photocatalytic Degradation of Methylene Blue Dye

In the present study, spike-like spherical iron manganite (FeMnO₃) nanoparticles were synthesized by chemical coprecipitation using chloride precursors subjected to calcination at 600°C for 3 h. The as-synthesized nanostructures were elaborately characterized for structural, morphological, elemental composition, optical, surface area, and availability of functional groups using x-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive spectroscopy (EDX), photoluminescence spectroscopy (PL), Brunauer–Emmett–Teller theory (BET), and Fourier-transform infrared spectroscopy (FTIR). XRD results showed a pure phase of FeMnO₃ with a cubic structure. FESEM images show the spike-like spherical morphology of the synthesized materials indicating higher surface roughness of the particles. PL spectroscopy shows strong absorption in the visible region of the solar spectrum. The photocatalytic response of the spike-like iron manganite nanoparticles was excellent for the degradation of methylene blue and methylene orange dyes under visible light. Owing to higher crystallinity and fewer defects in FeMnO_3, the heterostructures display nanoporous/mesoporous structures offering more active sites. A degradation efficiency of approximately 99% was observed within 180 min after light exposure. Iron manganite nanoparticles showed good stability and reusability up to three cycles. The facile preparation, environmentally favorable nature, and superb photocatalytic action of FeMnO₃ validate it as a promising candidate for photocatalytic applications in the visible range of the light spectrum.