Piezoelectricity-enhanced photocatalytic degradation performance of SrBi4Ti4O15/Ag2O p-n heterojunction

Ferroelectric materials will generate an internal electric field when subjected to force, thus assisting to separate the photogenerated carriers. Here, a ferroelectric SrBi4Ti4O15/Ag2O p-n heterojunction catalyst is designed, inducing the remarkable enhancement of photocatalytic degradation performance by piezoelectric effect under the direct current electric field. The polarized SrBi4Ti4O15/Ag2O degrades 99.54 % Rhodamine B (RhB) within 6 min when exposed to light and ultrasonic vibration simultaneously, with an ultra-high degradation rate constant (k = 0.8949 min-1), which is 3.24 times of photocatalytic degradation rate (0.2765 min-1) and 17.38 times of the piezocatalytic degradation rate (0.0515 min-1). Moreover, SrBi4Ti4O15/Ag2O piezo-photocatalyst presents excellent degradation effect on methylene blue (MB), methyl violet (MV), methyl orange (MO) and tetracycline (TC). The piezoelectric effect induced by ultrasonic vibration provides a built-in electric field, which significantly enhances the separation of photoexcited carriers, consequently improving the photocatalytic degradation properties of SrBi4Ti4O15/Ag2O. This study provides a valuable reference for designing efficient photocatalysts by coupling photocatalysis and piezoelectric effect.

Automated summary

By utilizing the piezoelectric effect, a ferroelectric SrBi4Ti4O15/Ag2O p-n heterojunction catalyst is designed, leading to a significant enhancement of photocatalytic degradation. It can degrade 99.54% Rhodamine B within 6 minutes with an ultra-high degradation rate constant (k = 0.8949 min-1), which is 3.24 times of the photocatalytic degradation rate and 17.38 times of the piezocatalytic degradation rate. Additionally, this catalyst shows excellent degradation effect on other organic pollutants as well. This study provides valuable insights for designing efficient photocatalysts by coupling photocatalysis and piezoelectric effect.