Inlay of Bi2O2CO3 nanoparticles onto Bi2WO6 nanosheets to build heterostructured photocatalysts

Abstract

Surface-dispersive-type Bi₂O₂CO₃/Bi₂WO₆ heterostructured nanosheets were successfully prepared via anion exchange in a hydrothermal process with the graphitic carbon nitride (g-C₃N₄) as a precursor of CO₃²⁻. The Bi₂O₂CO₃ nanoparticles (with diameters about 5 nm) were highly homogeneously dispersed and inlaid in the single-crystalline Bi₂WO₆ nanosheets. The composites with intimate interfacial contacts between Bi₂O₂CO₃ and Bi₂WO₆ exhibited superior visible light photocatalytic activity towards the degradation of rhodamine B (RhB). The composite nanosheets containing 7.86 wt% Bi₂O₂CO₃ showed the best performance and the degradation rate of RhB was 6 times faster than that with the bare Bi₂WO₆. The dramatic enhancement of the photocatalytic activity of the Bi₂O₂CO₃/Bi₂WO₆ photocatalysts can be attributed to the hetero-interfaces between Bi₂O₂CO₃ and Bi₂WO₆, their intrinsically layered structure, two-dimensional morphology and the effective separation of the photoinduced carriers at the interfaces and in the semiconductors. This method can be used to design and prepare other Aurivillius heterostructured semiconductors for efficient light harvesting and energy conversion applications.