Characterization and visible light photocatalytic mechanism of size-controlled BiFeO3 nanoparticles

• Size-controlled BiFeO3 nanoparticles were prepared by sol–gel method.
• The hydroxyl radicals were the main reactive species responsible for the pollutant degradation.
• BiFeO3 nanoparticles showed the size-dependent photocatalytic properties.

BiFeO3 nanoparticles with controlled particle size were synthesized via sol–gel method. The samples were characterized by X-ray powder diffraction, transmission electron microscope, Raman spectra, nitrogen adsorption technique and UV–vis diffuse reflectance spectra. Photocatalytic activity of BiFeO3 nanoparticles was further examined by monitoring the degradation of Rhodamine B dye in an aqueous solution under visible light irradiation. Through the calculation of band position and a number of diagnostic experiments, the photocatalytic mechanism of BiFeO3 nanoparticles was proposed in this study. It was found that the hydroxyl radicals originated from the photogenerated electrons were the main reactive species responsible for the pollutant degradation. Moreover, with the variations of annealing temperature and time, the average crystallite size, specific surface area and crystallinity of BiFeO3 nanoparticles could be changed, which thus affected the photocatalytic activity of the corresponding samples.

BiFeO3 nanoparticles showed the size-dependent photocatalytic properties, and the corresponding photocatalytic mechanism for the pollutant degradation was proposed.Figure optionsDownload as PowerPoint slide