Visible light-driven catalytic degradation of organic pollutants by S-scheme heterojunction Bi4O5I2/NaNbO3 enhanced by piezoelectric effect

The piezoelectric photocatalytic system can harness mechanical energy and carriers to degrade water pollution. Utilizing strong piezoelectric materials coupled with photocatalysts effectively addresses the recombination of photogenerated carriers. In this study, Bi₄O₅I₂, which responds to both visible light and piezoelectric stimuli, was synthesized by a solvothermal method. It was then further modified with the piezoelectric material NaNbO₃ to create a dual piezoelectric-responsive visible photocatalytic material Bi₄O₅I₂/NaNbO₃. Under the influence of an internal electric field and visible light irradiated induced by periodic ultrasonic vibration, the degradation rates of ARB and HCl-TC were exceeded 90 % within 90 min. The piezoelectric effect induced by ultrasonic vibration provided a robust internal electric field, significantly enhancing the separation of photoexcited carriers and thereby improving the catalytic activity of Bi₄O₅I₂/NaNbO₃. This work advances the effective purification of water pollution and offers valuable insights for developing efficient piezoelectric photocatalytic materials.