A facile ultrasonic-assisted fabrication of nitrogen-doped carbon dots/BiOBr up-conversion nanocomposites for visible light photocatalytic enhancements

A highly efficient novel photocatalyst consisting of nitrogen-carbon dots (N-CDs) and three-dimensional (3D) hierarchical BiOBr was synthesized via a simple ultrasonic-assisted method and used for the degradation of hazardous dyes. Deposition of N-CDs onto the surface of BiOBr was confirmed through structure and composition characterizations. The N-CDs/BiOBr composites exhibited superior activity for organic contaminant degradation under visible light and the 1 wt% N-CDs/BiOBr composite showed the highest degradation rate, indicating that N-CDs/BiOBr composites have great potential for application in mitigating hazardous contaminants. The N-CDs played an important role in improving the photocatalytic performance, owing to the enhancement of up-converted photoluminescence behavior as well as the efficient separation of photogenerated charge carriers originating from the intimately contacted interface. A possible photocatalytic mechanism was proposed based on the experimental results.