Photocatalytic performances of BiFeO3 particles with the average size in nanometer, submicrometer, and micrometer

Three different synthesis routes were taken to successfully prepare the BiFeO3 particles with the different morphologies and average size in 50, 500 nm, and 15 μm, respectively. The crystal structure was recognized to be a distorted rhombohedral one with the space group R3c. With the decrease in particle size, obvious decrease in peak intensity and redshift in peak position were observed for the Raman active bands. The narrow band gap was determined from the UV–vis absorption spectra, indicating the semiconducting nature of the BiFeO3. For photodegradation of dyes under visible irradiation in the presence of BiFeO3, the photocatalytic efficiency increased quickly with the decrease in size which may attribute to more surface active catalytic-sites and shorter distances carriers had to migrate to the surface reaction sites.