Internal Electric Field‐Induced High‐Efficiency Piezo‐Photocatalytic Performance in Bimetal‐Regulated Layered Perovskite SrBi₂Nb₂O₉

Abstract The piezoelectric effect is employed to enhance the photocatalytic process by enabling the efficient utilization of photogenerated electrons and holes. In this study, a defect‐engineered Na–Sm bimetal‐regulated layered ferroelectric material, SrBi₂Nb₂O₉, is synthesized using a molten salt process, and exhibits excellent piezo‐photocatalytic performance in the synergistic removal of uranium [U(VI)] and tetracycline (TC) from wastewater. The incorporation of the Sm dopant creates an intermediate band structure, while the Na doping introduces empty orbitals into the conduction band, thereby enhancing the electrical conductivity, improving the electron mobility, and supplying sufficient electrons to promote catalytic reactions. Moreover, the doping induces an additional internal electric field, which combines the embedded field along the b‐axis with the polarization along the a‐axis. This combined effect enhances the anisotropic migration of photogenerated electrons and holes, facilitating their spatial separation. The doped SrBi₂Nb₂O₉ can simultaneously remove 98% of U(VI) and degrade 99% of TC. Furthermore, a synergistic enhancement effect is observed between the U(VI) reduction and TC oxidation reactions, with the rate constant of U(VI) being 1.2 times higher than that of the individual system. This work presents an innovative strategy for designing layered ferroelectric catalysts able to simultaneously remove pollutants and optimize piezo‐photocatalytic redox reactions.