Fabrication of a three-dimensional BiOBr/BiOI photocatalyst with enhanced visible light photocatalytic performance

Abstract

Three-dimensional (3D) BiOBr/BiOI hierarchical microsphere photocatalysts were successfully synthesized via a facile one-pot solvothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and N2 adsorption–desorption isotherms. The photocatalytic activity was evaluated by the photocatalytic degradation of Rhodamine B (RhB) and tetracycline (TC) under visible light irradiation (λ>420nm). The 50% BiOBr/BiOI composite showed a higher photocatalytic removal efficiency of RhB and TC than 10% and 90% BiOBr/BiOI composites. RhB (C0=15mg/L) was degraded completely within 40min and over 83% of TC (C0= 40mg/L) was degraded within 50min using a catalyst quantity of 0.4g/L of 50% BiOBr/BiOI. The enhanced photocatalytic activity of the 50:50 composite was attributed to effective separation of photogenerated carriers and the balance between enhanced visible light absorption and decreased valence band (VB) edge potential.