Boosted elimination of florfenicol by BiOClxBr1-x solid solutions via photocatalytic ozonation under visible light

In this work, a series of BiOClxBr1-x (BCB) solid solutions are facilely designed for visible-light-driven photocatalytic ozonation (PCO) degradation of florfenicol (FF) in water environments, which could add to the library of efficient, cost-effective and robust nanocatalysts for water purification. BCB solid solutions in the structure of 2D nanosheets are achieved involving the etching of BiOBr "micro-flowers" with HCl at different concentrations, allowing a removal ratio of FF up to 97.3 % within 1 h, superior to bare BiOBr and bare BiOCl. A strengthened synergistic effect between photocatalysis and ozonation is substantiated, where the separation of photo-induced charge transfer is accelerated, the band gap is tuned and the utilization efficiency of ozone is enhanced. This facilitates the production of reactive oxygen species identified as •OH, •O2–, and 1O2 that will attack the FF molecule for degradation based on three pathways.