Discrete heterojunction nanofibers of BiFeO3/Bi2WO6: Novel architecture for effective charge separation and enhanced photocatalytic performance

Designing and constructing one-dimensional (1D) discrete heterojunctions comprise an ideal strategy to improve the charge-separation efficiency and enhance the photocatalytic activities of semiconductor materials. Here, a novel architecture of discrete heterojunction nanofibers (DH-NFs) was obtained by growing Bi2WO6 nanosheets (NSs) on electrospun BiFeO3 nanofibers (NFs) via solvothermal technology. The charge-separation efficiency of BiFeO3/Bi2WO6 DH-NFs was approximately 2 times higher than that of BiFeO3 NFs and Bi2WO6 NSs. As expected, the BiFeO3/Bi2WO6 DH-NFs exhibited enhanced photocatalytic activities for oxygen evolution and RhB degradation. The reaction rates of BiFeO3/Bi2WO6 DHNFs for oxygen evolution and RhB degradation were 18.3 and 36.7 times higher, respectively, than those of BiFeO3 NFs, and 31.9 and 8.7 times higher than those of Bi2WO6 NSs, respectively. The improved charge-separation efficiency and enhanced photocatalytic activities of BiFeO3/Bi2WO6 DH-NFs could be attributed to the following three points. The 1D heterojunctions could realize the separation and axial transport of photogenerated charges. The discrete structure could facilitate the spatial separation of redox reaction sites as well as photogenerated charges. The high surface area of BiFeO3/Bi2WO6 DH-NFs might provide more active sites for photocatalytic reaction. Moreover, the BiFeO3/Bi2WO6 DH-NFs possessed good recycling performance owing to the magnetic-separable property derived from the ferromagnetic behavior of BiFeO3. (C) 2020 Elsevier Inc. All rights reserved.