Carbon Quantum Dots Decorated Bismuth Oxychloride Nanocomposites with Enhanced Photocatalytic Activity Towards Pollutants Degradation and Mechanism Study

Utilization of visible light and the separation of electron-hole pairs is the forever theme of photocatalysis. In this work, a series of carbon quantum dots decorated bismuth oxychloride (CQDs/BiOCl) were prepared by solvothermal method, and served as photocatalysts for Rhodamine B (RhB) degradation under visible light. CQDs/BiOCl-8 (8 mL CQDs) can remove 97% RhB (20 mg/L) within 40 min, which is 11.3 times higher than pure BiOCl. This can be attributed to the fact that the excitation-independent up-conversion fluorescent characteristics of CQDs enable BiOCl to be excited by visible light. Furthermore, CQDs acted as electron libraries, which enhanced the separation of photoinduced electron-hole pairs in BiOCl. Quenching experiments confirmed that the superoxide (center dot O-2(-)) and hole (h(+)) were main reactive oxygen species (ROS) for RhB degradation. This study provides a strategy to design highly efficient photocatalysts for environmental remediation. [GRAPHICS] .