Piezotronic-enhanced photocatalytic performance of heterostructured BaTiO3/SrTiO3 nanofibers

Abstract

The piezoelectric effect can effectively modulate the energy band structure of the optoelectronic semiconductor and the transport behavior of carriers. Here, we propose a BaTiO 3 /SrTiO 3 nanocomposite, and effectively enhance its photocatalytic performance through piezoelectric effect. The heterostructured BaTiO 3 /SrTiO 3 nanofibers were prepared by electrospinning, and they were polarized by a high-voltage electric field. Under the co-excitation of ultrasonic and UV irradiation, the BaTiO 3 /SrTiO 3 nanofibers presented excellent degradation ability of pollutants in water. The BaTiO 3 /SrTiO 3 nanofibers can degrade Rhodamine B (RhB) dye by ~97.4% within 30 min under the combined action of ultrasonic and ultraviolet irradiation, which was 2.2 times that of pure SrTiO 3 nanofibers. The piezoelectric effect provides a built-in polarization field to improve the separation efficiency of photo-generated carriers. Moreover, DFT calculation results showed that piezoelectric potential can reduce the band gap width of the SrTiO 3 . This article provides a promising strategy for improving photocatalytic performance of nanocomposites through the use of mechanical energy. Here, we propose a heterostructured BaTiO 3 /SrTiO 3 nanocomposites that present enhanced photocatalytic performance through a piezotronic effect. The piezopotential generated in the BaTiO 3 /SrTiO 3 nanofibers under ultrasonic significantly improves the photocatalytic performance of the catalysts. • Heterostructured BaTiO 3 /SrTiO 3 nanofibers were prepared by electrospinning technique for piezo-photocatalysis. • Photocatalytic performance of BaTiO 3 /SrTiO 3 nanofibers were significantly improved through piezotronic effect. • Density functional theory (DFT) calculations prove that the band gap of SrTiO 3 can be modulated by an electric field.