Application of weak ferromagnetic BiFeO3 films as the photoelectrode material under visible-light irradiation

Abstract

Bi Fe O 3 films prepared by pulsed laser deposition on Pt∕TiO2∕SiO2∕Si substrates were studied as photoelectrode for water splitting. Under visible-light irradiation, the photocurrent intensity of the polycrystalline BiFeO3 film was found to double that of the amorphous one in a three-electrode cell. The incident photon to current conversion efficiency for the polycrystalline BiFeO3 electrode was approximately 16% at 350nm and 7% at 530nm at 1.5V (versus saturated calomel electrode). The ferromagnetism of the amorphous BiFeO3 film was an order of magnitude weaker than that of the polycrystalline one, supporting the “size effect” explanation for magnetic origin.