Amorphous/Crystalline Interface of Bi/Bi 4 NbO 8 Cl Heterostructure for Improved Piezo‐Photocatalysis

Abstract Efficient separation of photogenerated charges at the surface of photocatalysts is vital for achieving high photocatalytic activity. Here, a Bi/Bi 4 NbO 8 Cl heterostructure piezo‐photocatalyst with an amorphous/crystalline interface (acBi/BNC) is prepared by in situ reduction using Bi 4 NbO 8 Cl as a self‐sacrificial template. This ingenious design synergistically utilizes the advantages of the amorphous/crystalline interface structure, localized surface plasmon resonance effect, and piezoelectric field. The formation of amorphous/crystalline interfaces induces the generation of oxygen vacancies, and subsequently lattice distortions, thus improving the piezoelectric properties. Theoretical and experimental results demonstrate that the combination of piezoelectric field and amorphous/crystalline interface promotes the effective separation and migration of photogenerated charges between the bulk and surface of the catalysts. Under simultaneous light and ultrasound, the optimal heterostructure (acBi/BNC‐3) exhibit superior photodegradation efficiency of tetracycline reached 80% within 5 min, and the reaction rate (2.78 × 10 −1 min −1 ) is 7.8 and 5.4 times that of pure Bi 4 NbO 8 Cl (BNC) and crystalline Bi/Bi 4 NbO 8 Cl (cBi/BNC), respectively. Furthermore, the piezo‐photocatalytic tetracycline degradation efficiency surpasses those under individual photocatalysis and piezocatalysis conditions. This work provides a novel rational design to improve the spatial charge separation of Bi‐based catalysts and prepare high‐performance piezo‐photocatalysts via interface engineering.