Researchers from the National University of Singapore (NUS) and A*STAR developed a new method to create Quantum Dots from Graphene. The idea is to start with a C60 fullerene (a soccer ball like spherical carbon structure that costs of 60 carbon atoms) and 'open' them up (or decompose them) at high temperature using ruthenium as a catalyst.
The researcher performed the decomposition using a sparser coverage of fullerenes on the catalytic ruthenium surface than previously tried - which gave the fullerenes room to prevent carbon atoms from diffusing from one fullerene to the next.
By playing with the heating temperature, the researchers were able to change the quantum dots shape and size (which effect the wavelength emitted). Heating at 725K resulted in triangular graphene quantum dots, while further annealing at 825 K gave perfectly hexagonal dots just 5 nm in size.