Oxygen-vacancy-mediated photocatalytic degradation of tetracycline under weak visible-light irradiation over hierarchical Bi2MoO6@Bi2O3 core-shell fibers

Novel oxygen-vacancy-rich hierarchical Bi2MoO6@Bi2O3 core-shell fibers were prepared by the in situ growth of Bi2MoO6 nanosheets on Bi2O3 nanofibers via an electrospinning-calcination-solvothermal method. The in situ growth contributed to the formation of an intimate interface between Bi2MoO6 nanosheets and Bi2O3 nanofibers, thereby constructing an efficient 1D/2D heterojunction and obtaining a 3D hierarchical structure at the same time. More importantly, the growth of Bi2MoO6 nanosheets on Bi2O3 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 Bi2MoO6@Bi2O3 composite photocatalyst showed excellent photocatalytic performance under weak visible-light illumination, thus exhibiting potential for application in the degradation of antibiotics. This promising Bi2MoO6@Bi2O3 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 Bi2O3 and Bi2MoO6, respectively. Moreover, two main possible photocatalytic degradation pathways for TC over the Bi2MoO6@Bi2O3 photocatalyst were also proposed.

Automated summary

Novel oxygen-vacancy-rich hierarchical Bi2MoO6@Bi2O3 core-shell fibers were synthesized via an electrospinning-calcination-solvothermal method. The composite photocatalyst exhibited excellent photocatalytic performance and superior photocatalytic degradation rate for TC under weak visible-light illumination.