Microwave-Assisted Fabrication and Optical Tuning of Fe-Doped BiOBr Nanostructures for Visible-Light-Driven Photocatalysis

Iron (Fe)-doped bismuth oxybromide (BiOBr) semiconductors were successfully synthesized via a microwave-assisted method with Fe concentrations of 0.25 mol %, 0.50 mol %, and 0.75 mol % to enhance visible-light-driven photocatalytic degradation of Rhodamine B (RhB). The structural, morphological, and optical properties of the composites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), and ultraviolet-visible (UV-vis) spectroscopy. Among the composites, 0.50 mol % Fe-doped BiOBr exhibited the highest RhB degradation efficiency of 96.26% under visible light. The enhanced photocatalytic activity is attributed to more efficient charge carrier separation, improved light absorption, and the predominant roles of photogenerated holes (h⁺) and hydroxyl radicals (•OH) as the primary reactive species. These results demonstrate the potential of Fe-doped BiOBr as a promising solution for wastewater treatment.