Construction of a Z-scheme Cu2O/SrBi4Ti4O15 p–n heterojunction for enhanced visible light photocatalytic performance for doxycycline degradation

p–n heterojunction composites with high-charge-transfer efficiency have attracted considerable attention owing to their unique structure and interface interactions. Herein, a novel Z-scheme Cu 2 O/SrBi 4 Ti 4 O 15 p–n heterojunction was successfully constructed using the microwave hydrothermal method for DOC removal under visible light irradiation. The structure, composition, and photoelectric chemical properties of Cu 2 O/SrBi 4 Ti 4 O 15 nanocomposites were studied. The composites exhibited high photocatalytic activity for DOC, and 92.2% of DOC was decomposed within 60 min, which is 9.2 and 5.2 times higher than those of original Cu 2 O and SrBi 4 Ti 4 O 15 , respectively. The extraordinary degradation performance can be attributed to the formation of Z-scheme heterostructure. On the one hand, a unique interface structure can significantly enhance the number of active sites on the catalyst surface. On the other hand, Z-scheme heterostructure can accelerate generation and migration of the photoinduced carriers. Furthermore, the effects of operational parameters such as catalyst dosage, initial concentration, inorganic salts, and water sources, were investigated. Finally, a photodegradation mechanism of Z-scheme Cu 2 O/SrBi 4 Ti 4 O 15 p–n heterojunction for DOC was proposed.