Halide double perovskites Bi2WO6/Cs2AgBiBr6 with efficient charge separation and wide visible light absorption for high activity photocatalysis

Wide visible light absorption and effective spatial charge separation are also pursued for efficient photocatalytic degradation. In this work, Bi2WO6/Cs2AgBiBr6 (BWO/CABB) composites were prepared by simple hydrothermal, ball milling and thermal evaporation methods, and studied structural and optical properties using various characterizations. The activity of the obtained BWO/CABB nanocomposites for visible light degradation of organic pollutants was significantly improved. The optimal 3BWO/CABB composite has an ethanol-phase degradation efficiency of 97.4% for Rhodamine B (RhB) within 6 min, which is 3.63 and 1.71 times that of BWO and CABB, respectively, and showed good stability in 5 cycle experiments. 3BWO/CABB can also effectively degrade norfloxacin (NOR) (60 min, 63.1%) and rifampicin (RFP) (60 min, 93.21%). Radical trapping experiments showed that -OH and -O2- play a major role in photodegradation. The excellent photocatalytic performance of BWO/CABB is primarily due to the strong interaction between CABB nanosheets and BWO nanoflowers, the tight interfacial contact and the Z-type heterostructure formed by good Fermi level (EF) alignment, which enhances the visible light absorption and inhibits the recombination of carriers. The study of double perovskite BWO/CABB Z-type heterojunction can provide a reference for developing high-performance catalysts.