Piezotronic-enhanced photocatalytic performance of heterostructured BaTiO3/SrTiO3 nanofibers

The piezoelectric effect can effectively modulate the energy band structure of the optoelectronic semiconductor and the transport behavior of carriers. Here, we propose a BaTiO3/SrTiO3 nanocomposite, and effectively enhance its photocatalytic performance through piezoelectric effect. The heterostructured BaTiO3/SrTiO3 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 BaTiO3/SrTiO3 nanofibers presented excellent degradation ability of pollutants in water. The BaTiO3/SrTiO3 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 SrTiO3 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 SrTiO3. This article provides a promising strategy for improving photocatalytic performance of nanocomposites through the use of mechanical energy.