Enhanced photocatalytic degradation of organic pollutants using Fe2O3-TiO2 composites

Abstract

This study presents the synthesis and evaluation of Fe₂O₃–TiO₂ composites for the photocatalytic degradation of organic pollutants, using methylene blue (MB) as a model dye under ultraviolet (UV) light irradiation. The composites were prepared via a simple, cost- effective sol–gel method, ensuring uniform mixing and controlled particle properties. Structural and functional group characterization was performed using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). XRD confirmed the presence of anatase- phase TiO₂ and hematite-phase Fe₂O₃, while FTIR spectra indicated characteristic Ti– O and Fe–O bonds, suggesting strong interfacial interactions. Photocatalytic performance was systematically evaluated by varying pH (3, 6.09, 11), initial MB concentration (5, 10, 15 ppm), and catalyst dosage (0.5, 1.0, 1.5 g L⁻¹). The highest degradation efficiency (90.28%) was achieved at pH 11, 10 ppm dye concentration, and 1 g L⁻¹ catalyst dosage. Kinetic analysis revealed that the degradation followed pseudo-first-order kinetics, with a rate constant of 0.0198 min⁻¹. Control experiments confirmed that significant degradation occurred only when both UV light and the catalyst were present, verifying true photocatalytic activity. The enhanced performance is attributed to Fe₂O₃-induced charge separation, which reduces electron–hole recombination in TiO₂, promoting reactive oxygen species generation. The results indicate that Fe₂O₃–TiO₂ composites are efficient, stable, and potentially reusable catalysts, suitable for textile wastewater treatment and adaptable for broader environmental applications.