Ferroelectric spontaneous polarization steering charge carriers migration for promoting photocatalysis and molecular oxygen activation

摘要

Graphical abstractDisplay OmittedAbstractIntroducing a polarization electric field in photocatalyst system is regarded asa new concept for photocatalytic activity enhancement. In this work, we first unearth that the spontaneous polarization of ferroelectric BaTiO3promotes the photocatalytic and molecular oxygen activation performance of the narrow-band-gap semiconductor BiOI. Ferroelectric tetragonal-phase BaTiO3(T-BaTiO3) were prepared via calcination of nonferroelectric cubic-phase BaTiO3(C-BaTiO3), and their polarization ability was verified via ultrasonication-assisted piezoelectric catalytic degradation. Then, the C-BaTiO3/BiOI and T-BaTiO3/BiOI heterostructures are fabricated by a soft-chemical method. To disclose the influence of ferroelectric spontaneous polarization on charge movement behavior, the photocatalytic and molecular oxygen activation properties are monitored by degradation of methyl orange (MO) and superoxide radical (O2?) evolution under visible light irradiation (λ>420nm), respectively. The results demonstrated that T-BaTiO3/BiOI far outperforms C-BaTiO3