Imaging Science and Photochemistry ›› 2018, Vol. 36 ›› Issue (1): 108-116.DOI: 10.7517/j.issn.1674-0475.2018.01.011

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Synthesis of Water Soluble Nitrogen-doped Graphene Quantum Dots and Its Fluorescence Recognition of Pb2+

QIU Shenbao, WANG Sumin, WANG Qiguan, SHANG Jiayin, ZHANG Wenzhi, YANG Lei, FAN Yaru   

  1. School of Material and Chemical Engineering, Xi'an Technological University, Xi'an 710021, Shaanxi, P. R. China
  • Received:2017-03-29 Revised:2017-05-17 Online:2018-01-15 Published:2018-01-15

Abstract: In this paper, a facile approach for producing the nitrogen doped graphene quantum dots (N-GQDs) was carried out through solvothermal treatment. The graphene quantum dots (GQDs) derived from carbon fibers in N,N-dimethylformamide. The nitrogen content and the fluorescent quantum yield (QY) could be enhanced by prolonging the reaction time, and simultaneously the fluorescent color of the N-GQDs changed from orange to green and blue. Compared with low QY of 4.0% of GQDs, high QY of 30.1% could be reached by the blue fluorescent N-GQDs with the nitrogen content of 7.7% with solvothermal treatment of 24 h. Doping with nitrogen not only increase the content of C-N bonds, but also enhance the order of the structure, thus inceasing the fluorescent QY of N-GQDs. As a fluorescent probe, the N-GQDs could selectively detect the Pb2+ in aqueous solution. The N-GQDs fluorescence probe could be used to determine the level of Pb2+ in water sample in the range of 8.0×10-7 mol/L to 1.5×10-4 mol/L. Compared with the GQDs, the selectivity of the N-GQDs to Pb2+ was enhanced by the nitrogen doping.

Key words: nitrogen doped graphene quantum dot, recognition of Pb2+, fluorescence probe, solvothermal