Improved piezo-photocatalytic performance of ultra-thin BaTiO3 nanosheets with exposed {001} facets

Abstract

The photocatalytic efficiency of the catalyst is significantly influenced by the separation distance between photogenerated electrons and holes. In this study, ultrathin tetragonal BaTiO₃ nanosheets with a thickness of approximately 20 nm and exposed {001} facets were successfully synthesized via hydrothermal method. Subsequent photocatalytic degradation experiments revealed that the ultrathin nanosheet structure possesses enhanced deformability, significantly increased specific surface area, and improved light transmittance. Driven by out-of-plane piezoelectric fields perpendicular to the {001} facets, charge carriers migrate shorter distances toward the nanosheet surfaces to participate in catalytic reactions, effectively suppressing carrier recombination. Surface oxygen vacancies further facilitate charge separation. Under simultaneous ultrasonic and light irradiation, the BaTiO₃ nanosheets achieved 93.9 % methylene blue degradation within 60 min, outperforming both BaTiO₃ nanowires and nanoparticles. This microstructural optimization enhances the material’s piezo-photocatalytic performance, offering a novel strategy for catalytic enhancement. While the exposed {001} facets may reduce carrier migration distances, further investigation is required to elucidate the anisotropic charge transport mechanisms.