Exfoliated graphene ligands stabilizing copper cations

Exfoliated graphene ligands were prepared by heating exfoliated graphene sheets in ammonia gas at 1023 K. The functional groups of the functionalized exfoliated graphene ligands were mainly pyridine on the edges of the vacancy defects. Copper cations were coordinated with the ligands. Even after being heated at 773 K, coordinated copper did not show severe agglomeration. On the other hand, copper supported on exfoliated graphene sheets prepared by the conventional method agglomerated and ca. 20 nm of copper oxide was formed. This difference clearly shows that exfoliated graphene ligands stabilized copper cations.