Excellent piezo-photocatalytic performance of Bi4Ti3O12 nanoplates synthesized by molten-salt method

Bi4Ti3O12 is one of the Aurivillius-type layered perovskite oxides with superior photocatalytic effect, however, the further enhancement of this effect is limited by the high recombination rate of photo-generated carriers. Here, piezo-phototronic effect was employed to significantly improve the photocatalytic performance of Bi4Ti3O12 nanoplates synthesized by molten-salt method. Under light and ultrasonic excitations, the screening effect of the built-in electric field caused by ferroelectric polarization can be broken by the alternating piezoelectric potential due to the periodic mechanical stress, and thus the reaction rate k of piezo-photocatalytic degradation of RhB reaches 0.1414 min(-1) which is 5.6 times of piezocatalytic k value and 2.1 times of photo catalytic k value. This k value is much larger than that of Bi4Ti3O12 nanoplates and Bi4Ti3O12 nanoflowers synthesized by solid-state reaction method and hydrothermal method, respectively. Due to the good balance of size, shape, crystallinity and specific surface area, Bi4Ti3O12 nanoplates synthesized by molten-salt method exhibit better piezo-photocatalytic performance for degrading RhB. This work is helpful to develop other efficient piezo-photocatalysts.

Automated summary

In this study, the piezo-phototronic effect was employed to enhance the photocatalytic performance of Bi4Ti3O12 nanoplates. The synthesized nanoplates showed improved degradation rate of RhB under light and ultrasonic excitations. This work provides an efficient method to develop piezo-photocatalysts with superior performance.