Photocatalytic process represents a promising approach to overcome the pollution chal-lenge associated with the antibiotics-containing wastewater.This study provides a green,efficient and novel approach to remove cephalosporins,particularly cefoperazone sodium(CFP).Bi4O5Br2 was chosen for the first time to systematically study its degradation for CFP,including the analysis of material structure,degradation performance,the struc-ture and toxicity of the transformation products,etc.The degradation rate results indi-cated that Bi4O5Br2 had an excellent catalytic activity leading to 78％CFP removal com-pared with the pure BiOBr(38％)within 120 min of visible light irradiation.In addi-tion,the Bi4O5Br2 presents high stability and good organic carbon removal efficiency.The effects of the solution pH(3.12-8.75)on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline condi-tions.Combined with active species and degradation product identification,the photo-catalytic degradation pathways of CFP by Bi4O5Br2 was proposed,including hydrolysis,oxidation,reduction and decarboxylation.Most importantly,the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate ofβ-lactam bond cleavage in CFP molecule,quite different from the mostly previous stud-ies.Furthermore,the final products were demonstrated to be less toxic through the toxi-city analysis.Overall,this study illustrates the detailed mechanism of CFP degradation by Bi4O5Br2 and confirms Bi4O5Br2 to be a promising material for the photodegradation of CFP.