Enhanced photocatalytic activity in ferroelectric BiFeO3 nanoparticles treated by a corona poling method

BiFeO3 particles of about 50 nm were prepared by the sol-gel method with the calcination temperature of 450°C. The corona poling treatment was carried out on BiFeO3 nanoparticles for different electric fields and duration time. XRD analysis reveals that the BiFeO3 nanoparticles maintain the stable perovskite structure before and after the poling treatment. Raman and XRD analysis respectively show that the Bi–O bonds stretched and the lattice distorted for BiFeO3 nanoparticles with corona poling treatment. The poled BiFeO3 nanoparticles exhibit better photocatalytic kinetics in degradation of methyl orange (MO) dyes under the visible light irradiation for 3 h, which is about 5.1 times better relative to the BiFeO3 nanoparticles without the poling treatment. We conjecture that the enhanced internal electric fields produced by the corona poling process may be beneficial to the reduction of the combination of photogenerated electron-hole pairs resulting in the enhanced photocatalytic activity of BiFeO3 nanoparticles.