Enhanced visible-light-driven photocatalytic activity of BiFeO₃ via electric-field control of spontaneous polarization

Well-polarized BiFeO₃ nanoparticles have been successfully prepared by a facile electrical poling method with the assist of a soluble organic-inorganic composite film. From XRD, TEM and SEM studies, no significant change in the crystal structure or morphology was detected after the electrical poling process. The visible-light driven photocatalytic process of poled BiFeO₃ nanoparticles was accelerated by 2 times compared to unpoled BiFeO₃. By combining time-resolved photoluminescence (PL), photoinduced silver deposition testing and photoelectrochemical measurements, it can be revealed that the enhanced photocatalytic performance of poled samples can be properly attributed to the promoted separation and prolonged lifetime of the photogenerated carriers caused by the ferroelectric polarization. These findings may offer a new route to promote the photocatalytic or photoelectric performances of BiFeO₃ for advanced applications by adjusting the ferroelectric polarization.