BiOBr/Cu2S p-n heterojunction for efficient photodegradation of ciprofloxacin and tetracycline under visible light

With the increasing needs of people for a better life, the problem of water resources pollution has attracted wide attention. The construction of p-n heterojunction is an effective strategy to promote the removal of pollutants by photocatalysts. In this work, a series of BiOBr/Cu2S heterojunction photocatalysts with mass ratios of Cu2S have been synthesized successfully by a hydrothermal method combined with grinding method for photocatalytic degradation of tetracycline (TC) and ciprofloxacin (CIP). The results showed that BiOBr/Cu2S exhibited superior photodegradation efficiency of TC and ciprofloxacin CIP than BiOBr and Cu2S monomers. When the mass ratio of Cu2S is 0.15%, the visible degradation of CIP and TC are 79.2% in 90 min and 88.5% in 60 min. In addition, the effects of different inorganic ions and pH value on the photocatalytic performance of BiOBr/Cu2S were investigated. It was proved that superoxide free radical (•O2-) was the main active species by free radical trapping experiment. The photocatalytic degradation process was further evaluated by total organic carbon and mass spectrometry tests. This work provides a feasible construction strategy for photocatalysts with potential application in water resources pollutants.