Abstract:
We report on a non-covalent functionalization of
graphene foam (GF) synthesized via chemical vapour deposition
(CVD). The GF was treated with pyrene carboxylic acid
(PCA) which acted as a source of oxygen and/or hydroxyl
groups attached to the surface of the graphene foam for its
electrochemical performance improvement. The modified
graphene surface enabled a high pseudocapacitive effect on
the GF. A specific capacitance of 133.3 F g−1, power density ∼
145.3 kW kg−1 and energy density ∼ 4.7 W h kg−1 were
achieved based on the functionalized foam in 6 M KOH
aqueous electrolyte. The results suggest that non-covalent
functionalization might be an effective approach to overcome
the restacking problem associated with graphene electrodes
and also signify the importance of surface functionalities in
graphene-based electrode materials.