Alkali metal intercalation and rapid exfoliation of two-dimensional fullerene frameworks

K/Na intercalation of Mg 4 C 60 forms a Mg 2+ /K + (or Na + ) dual-ion lattice and stage-I intermediate at 400 °C. PhCN quenches charge, giving mono-/bilayer 2D-C 60 in 10 min. These 2D sheets show high photocurrent and reduced charge-transfer resistance.