Facial Synthesis and Photoreaction Mechanism of BiFeO3/Bi2Fe4O9 Heterojunction Nanofibers

Pure BiFeO 3, Bi 2 Fe 4 O 9, and BiFeO 3 /Bi 2 Fe 4 O 9 heterostructure nanofibers were successfully synthesized by a facile wet chemical process followed by an electrospinning technique. Compared with the pure BiFeO 3 and Bi 2 Fe 4 O 9 nanofibers, the introduction of Bi 2 Fe 4 O 9 in the BiFeO 3 makes its absorption edge red shift to absorb much more visible light, and improves its separation efficiency of photogenerated carrier. Besides, the as-obtained BiFeO 3 /Bi 2 Fe 4 O 9 nanofibers exhibit higher photocatalytic activity in both the degradation of Rhodamine B and H 2 evolution from water under visible-light irradiation. The BiFeO 3 /Bi 2 Fe 4 O 9 nanofibers exhibited about 2.7 times and 2.0 times higher H 2 evolution than that of pure BiFeO 3 and pure Bi 2 Fe 4 O 9 samples, respectively. The possible photoreactive mechanism of the BiFeO 3 /Bi 2 Fe 4 O 9 nanofibers was carefully investigated according to the results of photocatalytic and photoelectric performance, and a Z-scheme mechanism was proposed. Such BiFeO 3 /Bi 2 Fe 4 O 9 heterostructure and its composing strategy may bring new insight into the designing of highly efficient visible-light-responsible photocatalysts.