Fabrication of BiOBr/MoS2/graphene oxide composites for efficient adsorption and photocatalytic removal of tetracycline antibiotics

Bismuth oxybromide/molybdenum disulfide/graphene oxide (BiOBr/MoS2/GO) heterojunction composites were fabricated to modulate the adsorption ability and photocatalytic degradation performance toward oxytetracycline (OTC). The flowerlike BiOBr/MoS2/GO composites demonstrated excellent photocatalytic activies for the OTC degradation. Specifically, OTC, tetracycline, chlorotetracycline, and doxycycline were simultaneously removed with degradation rates higher than 98% under visible light irradiation within 40 min. Radical trapping experiments indicated that photogenerated holes (h+), hydroxyl radicals (OH), and superoxide radicals (O2−) played crucial roles in photocatalytic OTC degradation. Further, Possible transformation pathway and photocatalytic mechanism were proposed by investigating the intermediates in OTC degradation process.