Mechanism of interface engineering for ultrahigh piezo-photoelectric catalytic coupling effect of BaTiO3@TiO2 microflowers

The built-in electric field of piezoelectric material is a widely considered reason for improved photocatalytic performance. In this paper, BaTiO3@TiO2 microflowers are demonstrated ultrahigh piezophoto catalytic ability, of which the rate constant reaches 0.274 min(-1) for 10 mg/L rhodamine B degradation. The degradation rate is almost 0 in dark, but reaches 0.084 min- 1 under light irradiation. After deducting the difference in specific surface area, the rate constant of BaTiO3@TiO2 is 0.128 min-1 m(-2), which is 10 times higher than that of pure TiO2 (0.012 min- 1 m(-2)). These results indicate that the interface between BaTiO3 and TiO2 plays a major role to facilitate the separation of carriers, and it is also the uniqueness of this work. The mechanism of the interfacial enhanced piezophototronic effect is demonstrated by combining DFT modeling calculation and COMSOL simulation. This work proves that interface engineering is an effective route to enhance the performance of piezophotoelectric catalysis.