Coupling Enhanced Piezo-Photocatalysis on Robust Intergrowth Ferroelectric SrBi₈Ti₇O₂₇ Nanosheets

Piezo-photocatalysis is an emerging approach that combines the piezoelectric effect with the optical properties of a semiconductor to promote the effective separation of charge carriers. However, current piezocatalytic materials often suffer from poor catalytic efficiency and limited practicality due to a weak built-in electric field induced by mechanical energy. Herein, we introduce unique intergrowth ferroelectric semiconductor SrBi₈Ti₇O₂₇ nanosheets as a green and high-performance piezo-photocatalyst for CO₂ reduction and pollutant degradation. Compared to single ferroelectrics Bi₄Ti₃O₁₂ and SrBi₄Ti₄O₁₅, intergrowth ferroelectric SrBi₈Ti₇O₂₇, with the strongest spontaneous polarization electric field, achieves superior piezo-photocatalytic CO₂-to-CO conversion (361.34 μmol g^-1 h^-1). Moreover, our design also degrades high-concentration organic pollutants (100 mg/L) with up to ∼100% efficiency within 60 min, notably outperforming most standalone and untreated piezo-photocatalysts reported to date. These findings provide valuable insights for the development of highly efficient and multifunctional piezo-photocatalysts for green sustainable energy, environmental, and chemical applications.