Alkali Niobate and Tantalate Perovskites as Alternative Photocatalysts.

Alkali tantalates and niobates are listed as important photocatalysts for the development of renewable energy technologies and environmental remediation. Herein, the photocatalytic degradation of methylene blue dye in aqueous solution by using highly crystalline particles with perovskite-like structures, LiTaO3 , LiNbO3 , NaTaO3 , NaNbO3 , KNbO3 , and KTaO3 , is investigated. It is demonstrated that ferroelectric KNbO3 is the most efficient photocatalyst of those tested because it combines an electronic band structure that can respond successfully to UVA light with a relatively high surface energy that enhances the catalytic properties. Additionally, the built-in electric field due to internal polarization of ferroelectric particles may contribute to the unique properties of this functional photocatalyst. This work provides an ideal platform for the rational design of more efficient ferroelectric-based photocatalytic devices.