Carbon quantum dots decorated BiVO4 quantum tube with enhanced photocatalytic performance for efficient degradation of organic pollutants under visible and near-infrared light

Photocatalysis has been regarded as a sustainable and efficient technology for removing refractory pollutants in water. However, the performance of photocatalysis is usually limited by the fast recombination of photoinduced electron-holes and the narrow range of spectrum absorption. In this work, the visible-light-sensitive BiVO4 quantum tube (q-BiVO4) was decorated with the carbon quantum dots (CQDs) possessing unique upconversion fluorescence function for enhanced photocatalytic degradation of organic pollutants. Under visible light (>420nm) and even near-infrared light (>700nm) irradiation, the CQDs/q-BiVO4 composite displayed significantly enhanced performance compared with q-BiVO4 alone for the degradation of phenol and rhodamine B (RhB). The CQDs/q-BiVO4 with 2% CQDs loading exhibited the best performance, whose kinetic constants for phenol and RhB degradation were 3.0 and 2.4 times higher than that on q-BiVO4. The outstanding photocatalytic performance of CQDs/q-BiVO4 was ascribed to the quantum-sized BiVO4 and the dual function of CQDs, which not only served as the electron acceptor to separate the photoinduced electron-holes in q-BiVO4, but also improved the light absorption of q-BiVO4 through converting the near-infrared light into visible light. This work provides new insight into designing high-efficiency photocatalyst for enhanced environmental remediation.