Flower-like Bi2SiO5/Bi4MoO9 heterostructures for enhanced photocatalytic degradation of ciprofloxacin.

: Bi2SiO5/Bi4MoO9 photocatalysts with heterostructures were successfully prepared using a one-pot solvothermal route. The effect of molybdenum source on the composite formation was discussed. Under ultraviolet light irradiation, this Bi2SiO5/Bi4MoO9 heterojunction photocatalyst exhibited higher photocatalytic performance than Bi2SiO5 and Bi4MoO9 towards the degradation of ciprofloxacin (CIP). The dramatically enhanced photoactivity can be ascribed to the construction of a heterojunction interface between Bi2SiO5 and Bi4MoO9, which not only suppresses the recombination of photoexcited charge carriers but also enhances light absorption. In addition, for the view point of practicethe, the effect of initial CIP concentrations and coexisting ions on the photodegradation process using as-prepared Bi2SiO5/Bi4MoO9 heterojunction photocatalysts was explored. Trapping experiments demonstrate that the h+ and •O2- are the main active species in the photodegradation of CIP over Bi2SiO5/Bi4MoO9 heterojunctions. Meanwhile, the conduction band and valence band potentials values of Bi2SiO5 and Bi4MoO9 are measured by DFT calculation, DRS and Mott-Schottky curves. A possible photocatalytic mechanism for CIP degradation over the Bi2SiO5/Bi4MoO9 heterojunction was also proposed.