Comparative photocatalytic performance of iron nanoparticles biosynthesized from aqueous extracts of potato, potato peels, and leaves

This study presents an eco-friendly, cost-effective approach for synthesizing highly efficient nanocatalysts with the help of organic waste. Iron nanoparticles (INPs) were synthesized from aqueous extracts of potato, potato peel, and potato leaf and were evaluated for their photocatalytic efficiency for the degradation of methylene blue dye. X-ray Diffraction (XRD) confirmed Fe₃O₄ nanoparticles cubic crystal structure with the smallest crystallite size (9.52 nm) with potato peel, and Brunauer-Emmett-Teller (BET) analysis also showed the highest surface area (61.2 m²/g) for the same material. At the same time, other characterizations such as Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and Ultraviolet-Visible Spectroscopy (UV-Vis) for these nanoparticles were also performed, which provided insights into the chemical and physical composition and photoactivity. Photocatalytic tests demonstrated efficient methylene blue (MB) degradation under sunlight for all iron nanoparticles. The iron nanoparticle prepared using potato peel extracts achieved the highest degradation efficiency of 99 % in 120 min, with the highest first-order kinetics K = 0.0426 min^-1, attributed to its smallest crystallite size, highest surface area, and suitable band gap.