Metal-free CQDs introduced g-C3N4 nanosheets with enhanced photocatalytic reduction performance of uranium (VI)

• Published in: Journal of radioanalytical and nuclear chemistry Vol. 331; no. 5; pp. 2093 - 2104
• Main Authors: Liu, Jiayu, Zhang, Zhibin, Dong, Zhimin, Zhu, Xiang, Gao, Donglin, Cheng, Zhongping, Cao, Xiaohong, Wang, Youqun, Liu, Yunhai
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2022; Springer Nature B.V
• Subjects: Carbon; Carbon nitride; Chemistry; Chemistry and Materials Science; Diagnostic Radiology; Energy gap; Hadrons; Heavy Ions; Inorganic Chemistry; Melamine; Nanosheets; Nuclear Chemistry; Nuclear Physics; Photocatalysis; Photoluminescence; Physical Chemistry; Quantum dots; Uranium; Visible light irradiation; CQDs; U(VI); g-C; Photocatalytic reduction; N
• ISSN: 0236-5731; 1588-2780
• DOI: 10.1007/s10967-022-08264-7

The use of visible light to convert soluble U(VI) to insoluble U(IV) is a promising strategy for removing radioactive pollution. In this work, we used the top-down strategy to make carbon quantum dots and calcined with melamine to obtain carbon quantum dot modified carbon nitride (CD-C 3 N 4 ) composite photocatalytic material. The introduction of carbon quantum dots encourages not only the separation of photogenerated electrons and holes, but also the capture of light through up-conversion photoluminescence activity. When the carbon quantum dots doping amount rate of 5% (CD 5 -C 3 N 4 ), the energy gap was 2.2 eV, and the highest photocatalytic performance is shown. After irradiation for 120 min, the removal rate of U(VI) in the solution was 97.19%. Five photocatalytic cycle experiments show that the CD 5 -C 3 N 4 had perfect reusability. Moreover, through the active species trap experiment, the possible mechanism of enhancing photocatalysis was proposed and analyzed. This research has a broad application prospect in the field of radioactive pollution purification, and is of great significance for the design of other CQDs-based photocatalysts in radioactive contamination treatment.