Upgrading Biomass Wastes to Graphene Quantum Dots with White Light Emitting Features at the Solid State

The emergence of "green" materials has been attracting significant attention along the last few years for various applications. Here, we report a rapid, efficient and reproducible microwave-assisted synthesis of graphene quantum dots GQDs of identical features whatever the nature of biomass wastes investigated. The synthesized GQDs were fully characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The nanoparticles display narrow size of some nanometers with crystal lattices. Furthermore, the water-soluble particles show excitation-dependent photoluminescence ranging from blue to orange emission wavelength in solution. Interestingly, thin films display white light emission under 325 nm UV-light excitation, while aggregation-induced quenching is usually observed.