Synthesis of BiOBr x I 1−x solid solutions with dominant exposed {0 0 1} and {1 1 0} facets and their visible-light-induced photocatalytic properties

The BiOBrxI1−x solid solutions were successfully synthesized both in water and ethylene glycol (EG), using a facile solvothermal method. The as-prepared BiOBrxI1−x solid solutions were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), UV–vis spectrometer and so on. SEM images revealed that BiOBrxI1−x solid solutions formed 2D plate-like shape in water, and formed microspheres in EG solvent; except that BiOI formed nanoparticles in EG solvent. The photocatalytic performance of all the BiOBrxI1-x solid solutions samples were investigated by degrading phenol under visible light irradiation (λ > 420 nm). The BiOBr0.5I0.5 microspheres with highly exposed {1 1 0} facets showed the highest photocatalytic activity with phenol completely degraded within 80 min under visible light irradiation. In addition, a reasonable mechanism for the enhanced photocatalytic performance was also discussed in detail.