Photocatalytic degradation of tetracycline by using a regenerable (Bi)BiOBr/rGO composite

The development of advanced and robust photocatalysts is vital for efficient photocatalytic degradation of the antibiotic tetracycline. Herein, a hierarchical heterojunction (Bi)BiOBr/rGO was facilely synthesized by employing an in-situ reduction strategy. An obvious synergistic effect between adsorption and photocatalysis was observed. A >98% tetracycline degradation efficiency was obtained within 20 min, and high performance could be maintained for over 50 h in a continuous operation without any post-treatment. The experimental and DFT calculation results suggested that there existed a built-in electric field between the interfaces, leading to the fast electron migration. Furthermore, rGO could significantly enhance the tetracycline adsorption, and Bi largely suppressed the charge carrier recombination owing to the surface plasmon resonance (SPR) effect. A possible tetracycline degradation pathway was proposed based on the HPLC-MS analysis. This study provides pathways for the rational design of advanced and robust photocatalysts to effectively degrade emerging contaminants in practical continuous-flow configurations.