Photocatalytic degradation of methylene blue dye with biosynthesized Hematite α-Fe2O3 nanoparticles under UV-Irradiation
Mohamed Bilal Goudjil, Halima Dali, Souad Zighmi, Zineb Mahcène, Salah Eddine Bencheikh
Abstract
Nanoparticles (NPs) are currently extensively utilized in various fields, such as medicine, solar energy, water treatment, and pollution detection. In this study, hematite (α-Fe2O3) NPs were synthesized using a cost-effective and environmentally friendly method involving the utilization of a biomass filtrate of Mentha pulegium as a bio-reducer. The structural and optical properties of the α-Fe2O3 NPs were investigated using techniques such as X-ray diffraction (XRD), UV-Visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). X-ray diffraction analysis confirmed the crystalline nature of the α-Fe2O3 NPs, with a crystallite size ranging from 16.92 to 35.38 nm. The α-Fe2O3 NPs exhibited absorption at 290 nm, indicating a direct bandgap ranging from 3.25 to 3.90 eV and an indirect bandgap of 2.69 to 3.59 eV, as determined from the UV-Visible spectra. FTIR analysis revealed a peak at 486 cm−1, attributed to the vibration of the α-Fe2O3 NPs, confirming the formation of the nanoparticles. SEM imaging showed that the green-synthesized α-Fe2O3 NPs generally exhibited a hexagonal shape. The efficiency of the biosynthesized α-Fe2O3 NPs was evaluated for the rapid degradation of Methylene Blue (MB) dye, achieving a degradation rate of up to 78% after 120 min. These findings could serve as a foundation for the development of highly effective photocatalytic degradation methods that may be employed in the future for the removal of hazardous dyes from contaminated water.