A novel perovskite ferroelectric KNbO3-Bi(Ni1/2Ti1/2)O3 nanofibers for photocatalytic hydrogen production

Abstract Novel perovskite ferroelectric (1-x)KNbO3-xBi(Ni1/2Ti1/2)O3 nanofibers were synthesized by electrospinning for the first time. The synthesized 0.99KNbO3-0.01Bi(Ni1/2Ti1/2)O3 nanofibers displayed the optimal photocatalytic activity with a hydrogen production rate of 0.57 μmol·h-1 for 20 mg under visible light radiation. By first principles calculations, a midgap of Ni 3d was formed between the O 2p states at the valence band maximum and the Nb 4d states at the conduction band minimum due to the addition of Bi(Ni1/2Ti1/2)O3, which may be the principal reason for the visible light response in this work. In addition, the hydrogen production rate of polarized 0.99KNbO3-0.01Bi(Ni1/2Ti1/2)O3 nanofibers was twice as high as that of unpolarization under visible light irradiation, indicating that the internal dipole field can accelerate the separation of photogenerated electron-hole pairs. This may provide a new viewpoint for improving the visible light response of perovskite-oxide ferroelectrics.