Fabrication of a CuBi₂O₄/g-C₃N₄ p–n heterojunction with enhanced visible light photocatalytic efficiency toward tetracycline degradation

As the misuse and overuse of tetracycline (TC) contribute to water pollution, it is imperative to explore an efficient and cost-effective approach for the removal of TC in aqueous solution. Photocatalysis is a green and sustainable chemical technique because of its utilization of solar energy. From the view of practical application, it is significant to design a highly efficient, stable, eco-friendly and economical photocatalyst. In this work, CuBi₂O₄/g-C₃N₄ p–n heterojunctions with different CuBi₂O₄ content (10–90 wt%) were prepared via a facile calcining method. The CuBi₂O₄/g-C₃N₄ heterojunctions exhibit superior photocatalytic activity in the degradation of TC, compared with pristine CuBi₂O₄ and g-C₃N₄. The optimum photoactivity of 70 wt% CuBi₂O₄/g-C₃N₄ is up to 4 and 6 times higher than that of CuBi₂O₄ and g-C₃N₄, respectively. The enhanced photocatalytic activity can be attributed to p–n junction photocatalytic systems, which effectively promote charge carrier separation and transfer. It is anticipated that the design of CuBi₂O₄/g-C₃N₄ could offer the insight needed to construct inexpensive and highly efficient g-C₃N₄-based heterojunction photocatalysts, to relieve urgent environmental deterioration.