Investigation on photocatalytic activity of bio-treated α-Fe₂O₃nanoparticles using Phyllanthus niruri and Moringa stenopetala leaf extract against methylene blue and phenol molecules: Kinetics, mechanism and stability

In this article, Bio-treatment of α-Fe2O3 nanostructure using Phyllanthus niruri and Moringa stenopetala leaf extract as an effective reducing agent is carried out. The preparation of the rhombohedral α-Fe2O3 nanostructure is confirmed using X-ray diffraction analysis. The adsorption of biomolecules on the surface of the α-Fe2O3 nanostructure is confirmed using FT-IR. The chemical state analysis of green treated α-Fe2O3 nanoparticles was carried out using XPS techniques and it confirms the existence of Fe-2p and O-1s elements. The surface area of Moringa stenopetala leaf extract treated α-Fe2O3 nanoparticles were identified using BET analysis and it is found to be 58 m2/g. The formation of spherical shaped α-Fe2O3 nanoparticles was identified using HR-TEM analysis and EDX reveals the absence of any other impurities. The reactive species trapping experiment confirms the rapid production of O2•- and •OH radicals during photocatalytic process. The degradation efficiency of PNFO and MSFO against MB after 180 min was estimated to be 92% and 96%, respectively. The degradation efficiency of PNFO and MSFO against phenol after 240 min was estimated to be 90% and 92%, respectively.