Oxygen-vacancy-mediated photocatalytic degradation of tetracycline under weak visible-light irradiation over hierarchical Bi 2 MoO 6 @Bi 2 O 3 core–shell fibers

Novel oxygen-vacancy-rich hierarchical Bi 2 MoO 6 @Bi 2 O 3 core–shell fibers were prepared by the in situ growth of Bi 2 MoO 6 nanosheets on Bi 2 O 3 nanofibers via an electrospinning–calcination–solvothermal method. The in situ growth contributed to the formation of an intimate interface between Bi 2 MoO 6 nanosheets and Bi 2 O 3 nanofibers, thereby constructing an efficient 1D/2D heterojunction and obtaining a 3D hierarchical structure at the same time. More importantly, the growth of Bi 2 MoO 6 nanosheets on Bi 2 O 3 yielded superficial oxygen vacancies. Such a special morphology and defect structure could not only increase the light harvesting, but also promote the separation of photo-induced electrons and holes through a Z-scheme charge transfer mechanism. Therefore, the Bi 2 MoO 6 @Bi 2 O 3 composite photocatalyst showed excellent photocatalytic performance under weak visible-light illumination, thus exhibiting potential for application in the degradation of antibiotics. This promising Bi 2 MoO 6 @Bi 2 O 3 photocatalyst had a superior photocatalytic degradation rate of 96.3% for TC under 5 W LED visible-light irradiation for 3 hours, which was 6.0 and 4.9 times higher than those of pristine Bi 2 O 3 and Bi 2 MoO 6 , respectively. Moreover, two main possible photocatalytic degradation pathways for TC over the Bi 2 MoO 6 @Bi 2 O 3 photocatalyst were also proposed.