Green synthesis and use of Fe2O3 nanoparticles in the treatment of petroleum effluents by heterogeneous photocatalysis

The objective of this study was to develop a treatment for petroleum effluents via the use of Fe2O3 nanoparticles biosynthesized from extracts of A. alboviolaceum leaves as reducing and stabilizing agents. The obtained nanoparticles were characterized via ultraviolet (UV)‒visible spectroscopy, X-ray diffraction (XRD), X-ray fluorescence (XRF), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) to determine their structural and morphological properties. Their photocatalytic activity was evaluated by the degradation of hydrocarbons in petroleum effluents under solar irradiation for 180 min. The results obtained by UV‒visible spectroscopy revealed a surface plasmon resonance band at 515 nm. XRD was used to identify the nanoparticles that crystallized in a cubic crystal system (inverse spinel), whereas X-ray fluorescence and EDX were used to identify the chemical composition of the synthesized nanoparticles. The spherical morphology was determined via TEM. The average size of the nanoparticles, 70.43 nm, was determined via ImageJ software. The hemolytic activity of the biosynthesized nanomaterials revealed that they are not hemotoxic in vitro, and hydrocarbon degradation was observed after 120 min of sunlight irradiation in the presence of Fe2O3 nanoparticles, with a high degradation rate (71.9%). Compared with other chemical and physical methods, this study proposes a much simpler and less expensive method for synthesizing nanoparticles. This nanotechnological approach makes it possible to clean up hydrocarbon-contaminated effluents, thereby contributing to environmental protection.