Magnetically Separable Fe3O4/BiOBr Microspheres: Synthesis, Characterization, and Photocatalytic Performance for Removal of Anionic Azo Dye

Recyclable magnetic Fe3O4/BiOBr microspheres (m-Fe3O4/BiOBr MSs) were synthesized by a simple solvethermal method. The crystals' optical, morphology, and magnetic properties of m-Fe3O4/BiOBr MSs were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive analysis of X-rays, UV-vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller, and vibrating sample magnetometry techniques. An anionic dye, Congo red (CR), was selected as a model pollutant to evaluate the photocatalytic activity of m-Fe3O4/BiOBr MSs under simulated solar light irradiation. By calculation, the pseudo-first-order rate constant for photocatalytic degradation of CR was 0.0011 and 0.0046 min(-1) using pure BiOBr MSs and m-Fe3O4/BiOBr MSs, respectively. Enhanced photocatalytic activity of m-Fe3O4/BiOBr MSs can result from superior adsorption and transfer performance to organic contaminants in aqueous system. Both the h(+) radicals and O-2(center dot-) radicals were main active species that drive the photocatalytic decolorization of CR solution by m-Fe3O4/BiOBr MSs. Furthermore, the m-Fe3O4/BiOBr MSs can be easily recovered and recycled after the treatment process because of the presence of magnetic Fe3O4. This work suggests that m-Fe3O4/BiOBr MSs may be a promising photocatalyst for photocatalytic treatment of organic wastewater and other environmental remediation.