High-efficient one-pot synthesis of carbon quantum dots decorating Bi₂MoO₆ nanosheets heterostructure with enhanced visible-light photocatalytic properties

In this study, we reported a one-pot hydrothermal synthesis method for the preparation of nano-heterostructured composite carbon quantum dots (CQDs)/Bi₂MoO. Carbon quantum dots were in-situ synthesized and grafted onto Bi₂MoO₆ nanosheets via hydrothermal oxidation of glucose. For comparison studies, carbon quantum dots and Bi₂MoO₆ were also synthesized by the same way. The structures and compositions of the photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy and Raman spectroscopy. The photocatalytic activity of the photocatalysts was evaluated by degradation of Rhodamine B (RhB) and methylene blue (MB) under visible light irradiation. The resulting (CQDs)/Bi₂MoO₆ composites possess excellent photocatalytic activity and stability towards the degradation of Rhodamine B (RhB) and methylene blue (MB) in aqueous solution under visible light irradiation. When the mass ratio of Bi₂MoO₆ to glucose is 1:1, the composite showed the highest photocatalytic activity for RhB and MB degradation. A possible charge transfer and the degradation mechanism of CQDs/Bi₂MoO₆ materials were proposed to understand the relationship between structure and performance of the photocatalysts. The present work proposed a new method for the preparation of CQDs modified Bi₂MoO₆ using a facile method, which provided a new insight into the design and fabrication of advanced photocatalyst for energy and environmental application. - Highlights: • CQDs/Bi₂MoO₆ heterostructure are synthesized via a facile method. • The optimal ratio of CQDs and Bi₂MoO₆ are determined. • The roles of active species and CQDs in the photocatalytic process are discussed. • The charge transfer and degradation mechanism are explored.