Electrospun Fiber Membranes of Fe2O3/ZnO with High Photocatalytic Activity for Wastewater Treatment Application under Visible Light Irradiation

Abstract

Fe₂O₃/ZnO fiber membranes, characterized by their high specific surface area and expanded UV–Vis absorption spectrum, were successfully synthesized through a process of electrospinning followed by calcination. The diameters of Fe₂O₃/ZnO fibers are approximately 150 nm, and the specific surface areas of Fe₂O₃/ZnO fiber membranes are around 29 m²/g. XRD, SEM, and XPS results confirm the formation of a heterojunction between ZnO and α-Fe₂O₃. Compared with pure ZnO fiber membrane, the UV–Vis absorptions of the Fe₂O₃/ZnO fiber membranes are extended, and transient photocurrent intensities are significantly increased from 0.65 mA/cm² to 0.86 mA/cm². Free radical capture experiments further reveal the generation of abundant •OH radicals, which play a crucial role in enhancing the photocatalytic performance of these Fe₂O₃/ZnO fiber membranes. Optimization studies have determined that the optimal molar ratio of Fe to Zn is 8 mol% in the Fe₂O₃/ZnO heterojunction, which corresponds to a 45% improvement in photocatalytic degradation efficiency for MB. Furthermore, the remarkable cycling stability of the Fe₂O₃/ZnO fiber membranes demonstrate their substantial potential for photocatalytic dye wastewater treatment.