Preparation of BiOBr by solvothermal routes with different solvents and their photocatalytic activity

In this paper, a series of BiOBr photocatalysts have been synthesized by solventhermal method using different solvents (water, ethanol, isobutanol, ethylene glycol, and glycerol), and were characterized by X-ray diffraction, scanning electron microscope, UV-visible diffuse reflectance spectra, and X-ray photoelectron spectroscopy. It is found that the solvent plays a key role to tune the morphology, crystal growth, and surface nature of BiOBr. The photodegradation rate of reactive brilliant blue (KN-R) over BiOBr photocatalysts prepared by water, ethanol, isobutanol, ethylene glycol, and glycerol as solvents are 52.5%, 65.0%, 54.6%, 66.1%, and 90.9%, respectively, under sunlight irradiation for 120 min. The flower-like hierarchical BiOBr prepared by glycerol as solvent exhibited better photocatalytic activity for the degradation of reactive brilliant blue (KN-R) under sunlight irradiation. The excellent photocatalytic activity of BiOBr prepared by glycerol as solvent can be attributed to its high exposed active face, little crystal size, and abundant oxygen vacancies. Furthermore, recycled photodegradation experiments indicated the catalyst did not exhibit any significant loss of photocatalytic activity after five recycles, which confirmed the photocatalyst is essentially stable. (C) 2015 AIP Publishing LLC.