A One-step Hydrothermal Method of Nitrogen-doped Graphene Quantum Dots Decorated Graphene for Fabrication of Paper-based Fluorescent Composite

A facile approach for producing fluorescent composite paper containing nitrogen-doped graphene quantum dots (N-GQDs) and graphene on the surface of the modified fibers was implemented from the exfoliation of graphite oxide (GO) using a one-step hydrothermal method. The properties of the composite paper were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV), photoluminescence spectroscopy (PL), and confocal laser scanning microscopy (CLSM). The results indicated that the GO was reduced to graphene sheets, and the N-GQDs nanoparticles were deposited on the surface of these sheets. The composite paper remained undamaged, with a three-dimensional structure and smooth fibers during the hydrothermal process, and the average particle size of N-GQDs was less than 10 nm. Photoluminescence measurements showed that the composite paper had a strong ultraviolet absorption in the range of 200 to 340 nm, and the band edge emission occurred at 475 nm. The CLSM image of composite paper exhibited a well-defined excitonic emission feature with an excitation wavelength of 405 nm.