Photocatalytic degradation of synthetic dyes using iron (III) oxide nanoparticles (Fe2 O3 ‐Nps) synthesised using Rhizophora mucronata Lam

Biosynthesis of nanoparticles through plant extracts is gaining attention due to the toxic free synthesis process. The environmental engineering applications of many metal oxide nanoparticles have been reported. In this study, iron oxide nanoparticles (Fe₂ O₃ ‐Nps) were synthesised using a simple biosynthetic method using a leaf extract of a mangrove plant Rhizophora mucronata through reduction of 0.01 M ferric chloride. Fe₂ O₃ ‐Np synthesis was revealed by a greenish colour formation with a surface plasmon band observed close to 368 nm. The stable Fe₂ O₃ ‐Np possessed excitation and emission wavelength of 368.0 and 370.5 nm, respectively. The Fourier‐transform infrared spectral analysis revealed the changes in functional groups during formation of Fe₂ O₃ ‐Np. Agglomerations of nanoparticles were observed during scanning electron microscopic analysis and energy‐dispersive X‐ray spectroscopic analysis confirmed the ferric oxide nature. The average particle size of Fe₂ O₃ ‐Np based on dynamic light scattering was 65 nm. Based on transmission electron microscopic analysis, particles were spherical in shape and the crystalline size was confirmed by selected area electron diffraction pattern analysis. The synthesised Fe₂ O₃ ‐Np exhibited a good photodegradation efficiency with a reduction of 83 and 95% of phenol red and crystal violet under irradiation of sunlight and florescent light, respectively. This report is a facile synthesis method for Fe₂ O₃ ‐Np with high photodegradation efficiency.Inspec keywords: photochemistry, dyes, nanofabrication, transmission electron microscopy, scanning electron microscopy, nanoparticles, iron compounds, X‐ray diffraction, catalysts, catalysis, particle size, X‐ray chemical analysis, electron diffraction, Fourier transform infrared spectra, surface plasmonsOther keywords: energy‐dispersive X‐ray spectroscopic analysis, ferric oxide nature, transmission electron microscopic analysis, selected area electron diffraction pattern analysis, iron oxide nanoparticles, plant extracts, toxic free synthesis process, metal oxide nanoparticles, metal nanoparticles, nanofiltration, nanobiocides, Rhizophora mucronata Lam, crystalline size, phenol red, crystal violet, sunlight irradiation, florescent light, scanning electron microscopic analysis, Fourier‐transform infrared spectral analysis, surface plasmon, ferric chloride, leaf extract, nanocatalysts, nanoadsorbents, photocatalytic degradation, synthetic dyes, mangrove plant, water remediation, wastewater pollutant, wavelength 370.5 nm, wavelength 368.0 nm, Fe₂ O₃