Detailed characterization including LDI-TOF MS, TEM, AFM, STM, XPS, DLS, FT-IR, and Raman spectroscopy analyses revealed the formation of aggregated small fragments consisting of carbon, oxygen, and hydrogen elements, which favored the production of graphene QDs.
More importantly, the graphene QDs exhibited strong luminescence properties when excited at 340 nm.
The highly oxygenated graphene QDs showcased their broad prospects for modifications through successful functionalization reactions. The luminescence properties varied according to the types of chemical treatments, whereby hydroxylamine-functionalized graphene QDs showed a blue-shift of the emission maximum, while hydrazine-reduced graphene QDs showed a red-shift of the emission maximum.
All in all, the simplicity of this method in producing graphene QDs shows potential for further development for integration into practical devices or applications including optoelectronics and biological labeling.