Multilayer structured bismuth silicate inverse opal film with improved piezo-photocatalytic performance for wastewater purification and dyes removal

Suppressing the recombination of photogenerated charge carriers is thought to be possible by combining the photocatalytic method with the piezoelectric action of piezoelectric semiconductors. A new piezo-photocatalyst, Bi₂SiO₅ inverse opal film, was prepared by inverse template method. The introduction of 3D ordered inverse opal structure was favorable for light harvesting. The unique two-dimensional layered structure of Bi₂SiO₅ facilitates electron-hole (e^--h⁺) pair separation. The degradation efficiency of Bi₂SiO₅ inverse opal film is 15 times higher than that of planar- Bi₂SiO₅ film under UV light alone. When co-excited by UV light and mechanical energy (ultrasonic vibration), the Bi₂SiO₅ inverse opal film demonstrated a significantly accelerated degradation rate of RhB compared with planar Bi₂SiO₅ film. The enhanced piezo-photocatalytic efficiency resulted from the effective separation of photogenerated electron-hole pairs in the Bi₂SiO₅ inverse opal under the inherent piezoelectric field. Consequently, our work offers fresh perspective on piezo-photocatalytic materials based on Bi₂SiO₅ for effective wastewater treatment.