Photocatalytic Degradation of Methyl Orange over BiOClxBr1-x (0 x 1) Solid Solutions

Abstract

Objective: Due to possessing the layered structure and tunable band gap, Bismuth oxyhalide BiOX (X = Cl, Br, I) has been regarded as a novel photocatalyst with excellent photocatalytic activity for the degradation of organic pollutants. Methods: In this study, BiOClxBr1-x (0≤x≤1) solid solution photocatalytic materials were synthesized by a simple alcoholysis method at room temperature. The as- synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and diffuse reflectance spectroscopy (DRS). The photocatalytic activity of samples was evaluated by degrading Methyl Orange (MO) under the irradiation of UV light. Results: XRD results indicated that the as-prepared photocatalysts were tetragonal crystal structure. SEM observation showed that the particles of samples were regular with lamellar plate morphology. DRS calculation exhibited that their band gaps ranged between 3.23 and 2.83 eV with different Cl/Br ratios. The photocatalystic tests showed that BiOCl0.5Br0.5 exhibited the best photocatalystic activity with the MO discoloration ratio near 90% within 90 min irradiation at pH=7. Conclusion: BiOClxBr1-x (0≤x≤1) solid solution photocatalytic materials might have potential applications in the sewage treatment.