Enhanced catalytic performance of Ag2O/BaTiO3 heterostructure microspheres by the piezo/pyro-phototronic synergistic effect

The introduction of a built-in electric field by using ferroelectric materials is an efficient way to modulate the carrier generation and transportation behavior of photocatalysts. Here, we propose a hydrothermal-synthesized Ag2O/BaTiO3 heterostructure composite, whose photocatalytic performance can be largely enhanced by a four-way coupling effect among piezoelectricity, pyroelectricity, semiconductor and photoexcitation, referred as the piezo/pyro-phototronic synergistic effect. The photoelectrochemical (PEC) test of Ag2O/BaTiO3 shows a high photocurrent density of 3.48 mA/cm2 at 1.5 VSCE, which is 1.5 and 1.3 times as high as that of pristine BaTiO3 and Ag2O, respectively, and the transient photocurrent density of the composite at 0.5 VSCE is 20 times higher than that of the pure BaTiO3. Under varying temperature field and ultrasonic excitation condition, the photocatalytic degradation efficiency of the Ag2O/BaTiO3 composite is enhanced greatly when compared to that under only light illumination condition. This enhancement can be attributed to the attraction and release process of photogenerated carriers during the varying temperature field and ultrasonic excitation cycling. These results indicate that the ferroelectric heterostructure composites can act as a promising photocatalyst in wastewater treatment field under different environmental conditions.