Preparation and characterization of Bi2SiO5/BiVO4 n–n isotype heterojunction composites as a visible-light-induced photocatalyst for tetracycline and levofloxacin degradation

Semiconductor photocatalysis is a promising method to solve the problem of antibiotic pollution in water. A series of Bi 2 SiO 5 /BiVO 4 composite photocatalysts for tetracycline and levofloxacin degradation are prepared by a two-step hydrothermal method. Analysis results show that the as-prepared Bi 2 SiO 5 /BiVO 4 (2:3) hybrid exhibits better photocatalytic activity than pure samples under visible light illumination. The photocatalytic degradation efficiency of the as-prepared composite shows the maximum of 72.2% within 120 min for tetracycline, which is higher than 43.5% of pure Bi 2 SiO 5 and 67.2% of pure BiVO 4 , respectively. Furthermore, it is 80.3% within 120 min for levofloxacin, which is higher than 7.6% of pure Bi 2 SiO 5 and 69.7% of pure BiVO 4 , respectively. The formation of n–n isotype heterojunction at the interface of Bi 2 SiO 5 and BiVO 4 in the as-prepared composites causes to the improvement of the transport rate and separation efficiency of the photogenerated electron and hole pairs. In addition, the holes play a dominant role in the photocatalytic degradation process. This work will provide a reference for the study of visible light driven photocatalysts to solve antibiotics pollution in water.