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.
Recently, it is shown that the thin films of BiFeO 3 –BaTiO 3 –SrTiO 3 have ultrahigh-energy storage density. However, the energy storage properties of BiFeO 3 –BaTiO 3 –SrTiO 3 ternary bulk ceramics have not been studied. In this work, the BiFeO 3 –BaTiO 3 –SrTiO 3 ceramics have been prepared by a conventional solid-state reaction method and the dielectric and electrical energy storage properties have been studied in detail. The ceramic with the composition of 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 is experimental evidenced to be the best with the highest dielectric permittivity in the ternary system. To suppress the dielectric loss and leakage current, 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 has been doped with Mn. Mn-doped ceramics have the same perovskite structure but the fine grains are formed and the number of pores decreases. Mn-doping reduces dielectric loss, enlarges the thermally stable zone of the dielectric, and improves the electrical energy storage density simultaneously. 2 mol% Mn-doped 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 has the most optimized electrical energy storage properties. The energy storage density is 1.33 J/cm 3 and the efficiency is 88.5% at 185 kV/cm. The discharge energy density is 2.7 times that of undoped 0.25BiFeO 3 –0.30BaTiO 3 –0.45SrTiO 3 and 90% stored energy can release in 120 ns.
危险品化学品经营许可证（带存储）