Piezoelectric potential activated interfacial electric field in BiFeO₃@BaTiO₃ heterojunction for rapid and round-the-clock photocatalytic degradation of organic pollutants

The highly efficient degradation and purification of organic pollutants in waste water by photocatalysis is still challenging. Herein, a piezoelectric potential activated interfacial electric field (IEF) was constructed to endow BiFeO₃@BaTiO₃ (BFO@BTO) heterojunction as a round-the-clock photocatalyst for polluted water remediation. BFO@BTO heterojunction composited with BiFeO₃ nanoparticles decorated on the surface of BaTiO₃ nanorods, shortens the carrier migration path. More importantly, IEF can be activated and reconstructed under ultrasonic waves irradiation, leading to the lower potential barrier and the enhanced separation efficiency for photogenerated carriers. Impressively, the degradation rate constant k value of BFO@BTO heterojunction reached up to 0.038 min^-1, which was 1.9 and 7.0 times higher than that of piezocatalysis and photocatalysis alone, respectively. It also exhibited excellent stability in three light-dark cycles for high concentration (25 mg·L^-1) of rhodamine B and tetracycline hydrochloride. This study provides a promising strategy to design highly active photo-assisted piezocatalysts for environmental energy utilization and round-the-clock catalysis.