Visible‐Light‐Driven p–n Type BiMSbO6(M=Ti, Sn)/BiOBr Heterojunction Photocatalyst toward Degradation of Levofloxacin

Abstract A new visible light‐driven p‐n type BiMSbO 6 (M=Ti, Sn)/BiOBr heterojunction photocatalyst was prepared in this paper. The XRD results showed that pure BiTiSbO 6 and pure BiSnSbO 6 crystallized well with the pyrochlore‐type structure, stable cubic crystal system by space group Fd3 m and the XPS results further confirmed its high crystallinity. The crystal parameters of pure BiSnSbO 6 and pure BiTiSbO 6 were 10.23459 Å and 9.87708 Å, respectively. After visible light irradiation for 100 minutes, the removal rate of levofloxacin with 5 wt%, 10 wt% or 20 wt% BiMSbO 6 (M=Ti, Sn)/BiOBr heterojunction photocatalyst could all reach more than 85%, which was far higher than that with pure BiSnSbO 6 (4.79%) as a photocatalyst or that with pure BiTiSbO 6 (5.35%) as a photocatalyst. In addition, the form of p‐n heterojunction improved the reusability of pure BiOBr. After four cycles of photodegradation experiments for levofloxacin, the removal rate of levofloxacin with 20 wt% BiTiSbO 6 /BiOBr heterojunction photocatalyst or 10 wt% BiSnSbO 6 /BiOBr heterojunction photocatalyst decreased by 11.48% or 11.02%. However, the removal rate of levofloxacin with pure BiOBr decreased by 18.68%. Moreover, h + contributed the most during the degradation procedure of levofloxacin with BiMSbO 6 (M=Ti, Sn)/BiOBr heterojunction photocatalyst. Eventually, working mechanism of BiMSbO 6 (M=Ti, Sn)/BiOBr heterojunction photocatalyst was described in detail.