Photoelectrochemical properties of Fe2O3/BiFeO3 ferroelectric composites

Key words:  ferroelectric composite material  photoelectrochemical property  Fe₂O₃ nanorod

Abstract:

Iron oxide nanorod array was prepared by hydrothermal method, which was then modified by spin-coating of bismuth ferrite sol-gel solution. And the photoelectrochemical performance of Fe₂O₃ was greatly improved due to the semiconductor composition. The phase and morphology were characterized by XRD and SEM. The linear volt-ampere curves and AC impedance of the composites were tested by electrochemical workstation. The enhancement mechanism of photoelectrochemical properties of composites was investigated. The results show that the optimal annealing temperature of Fe₂O₃ /BiFeO₃ composite is 600 ℃. At this temperature, the carrier concentration and photocurrent density increase obviously. At room temperature, the 3 layers BiFeO₃ presents the best photoelectrochemical properties, and the photo-current density reaches 0.018 mA/cm², which is 1.8 times higher than Fe₂O₃. At 90 ℃, the 3 layers BiFeO₃ has the best photoelectrochemical performance, and the current density is 0.028 mA/cm², which is 1 times higher than the light response current density at room temperature. Ferroelectric polarization (20 V) improves the photoelectrochemical performance of the composite.