Cage-opening fullerene provide fluorescent graphene quantum dots

(Nanowerk News) New work by an international research team has demonstrated the simultaneous oxidation and cage-opening of fullerene C60 to provide graphene quantum dots.
Reporting their findings in ACS Nano ("Synthesis of Strongly Fluorescent Graphene Quantum Dots by Cage-Opening Buckminsterfullerene"), the team synthesized graphene quantum dots (QDs) by treating fullerene C60 with a mixture of concentrated sulfuric acid, sodium nitrate, and potassium permanganate.
Treatment of fullerene C60 with a mixture of strong acid and chemical oxidant induced the oxidation, cage-opening, and fragmentation processes of fullerene C60. (© ACS)
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.
Source: American Chemical Society