Hydrothermal deposition synthesis of dual-mode luminescent material GdVO4 :Eu3+ /carbon dots with optimal luminescence and its application in anti-counterfeiting.

Abstract

To obtain optimal luminescence, 0.12 g of GdVO4 : 3% Eu3+ nanocrystals (NCs) and different volumes of nitrogen-doped carbon dots (N-CDs) crude solution were used as precursors, and the composite synthesized by hydrothermal deposition method shows optimal luminescence when 11 mL(2.45 mmol) crude solution was used. Besides, similar composites with the same molar ratio as GVE/cCDs(11) were also prepared with hydrothermal and physical mixing process, respectively. Based on the test results of XRD, XPS and PL spectra, one can find that for the composite GVE/cCDs(11), the highest (lowest) peak intensity of C-C/C=C (C=O/C=N) bond, which is 1.18 (0.75) times that of GVE/cCDs-m, indicates the most N-CDs deposition, and lead to their highest emission intensity under 365 nm excitation though nitrogen atoms in the composite are shed off slightly during the deposition process. Finally, as can be seen from the designable patterns for security application, the optimally luminescent composite is one of the most promising candidates in the anti-counterfeiting field.