Ferroelectric polarization-enhanced photodegradation performance for dyes in BaTiO3/AgAlO2 heterostructure

Introducing an internal electric field into photocatalysts is an efficient strategy to inhibiting the charge carrier recombination which is the obstacle to the photocatalytic technology. Herein, we propose to construct BaTiO3/AgAlO2 heterostructure with improved photocatalytic performance through a polarization effect. The ferroelectric BaTiO3 particles with nanocube morphology are distributed over ellipsoid-like AgAlO2. The UV–vis absorption edges extend from 415 to 545 nm owing to the energy band overlap. The ultrasound-assisted photocatalysis efficiency of methyl blue under BaTiO3/AgAlO2 is increased by 22 %. Photoelectrochemical results indicate that the separation efficiency of photoinduced carriers is enhanced by the polarization effect. Moreover, the photocurrent of the BaTiO3/AgAlO2 after polarization is increased by 1.6 times of that before polarization. Piezoelectric force microscope shows that the phase angle has a great change, confirming the polarization switching process. The butterfly-shaped displacement-voltage hysteresis loop confirms the local piezoelectric response originated from BaTiO3.