Improved photoredox activity of the 2D Bi 4 Ti 3 O 12 -BiVO 4 -Bi 4 V 2 O 10 heterostructure via the piezoelectricity-enhanced charge transfer effect.

Introducing piezoelectric materials with the built-in electric field caused by mechanical force has been confirmed as an effective strategy to boost the separation efficiency of photoexcited charge carriers that determines the photocatalytic performance. In this study, we introduced Bi ₄ Ti ₃ O ₁₂ with superior piezoelectric properties into BiVO ₄ -Bi ₄ V ₂ O ₁₀ materials to synthesize a 2D Bi ₄ Ti ₃ O ₁₂ -BiVO ₄ -Bi ₄ V ₂ O ₁₀ photocatalyst via a facile hydrothermal method. Compared with bare BiVO ₄ , the Bi ₄ Ti ₃ O ₁₂ -BiVO ₄ -Bi ₄ V ₂ O ₁₀ piezo-photocatalytic activity towards Cr(VI) removal and oxygen evolution is boosted remarkably under both illumination and ultrasound treatments. The promoted photocatalytic activity can be ascribed to the accelerated photoexcited carrier separation efficiency driven by the polarization electric field and the synergy effect in the heterostructure. This work provides a simple and sustainable strategy for the design and development of piezo-photocatalysts with high photoredox activity capacity.