In situ preparation of visible-light-driven carbon quantum dots/NaBiO hybrid materials for the photoreduction of Cr(VI).

In this study, different carbon quantum dots (CQDs)/NaBiO hybrid materials were synthesized as photocatalysts to effectively utilize visible light for the photocatalytic degradation of contaminants effectively. These hybrid materials exhibit an enhanced photocatalytic reduction of hexavalent chromium (Cr(VI)) in the aqueous medium. Zero-dimensional nanoparticles of CQDs were embedded within the two-dimensional NaBiO nanosheets by the hydrothermal process. Compared with that of the pure NaBiO nanosheets, the photocatalytic performance of the hybrid catalysts was significantly high and 6 wt.% CQDs/NaBiO catalyst exhibited better photocatalytic performance. We performed the first-principles density functional theory calculations to study the interfacial properties of pure NaBiO nanosheets and hybrid photocatalysts, and confirmed the CQDs played an important role in the CQDs/NaBiO composites. The experimental results indicated that the enhanced reduction of Cr(VI) was probably due to the high loading of CQDs (electron acceptor) on NaBiO which made NaBiO nanomaterials to respond in visible light and significantly improved their electron-hole separation efficiency.