Electrochemical performance of graphene and copper oxide composites synthesized from a metal–organic framework (Cu-MOF)

A composite made from copper oxide (CuO) and exfoliated graphene (G) was synthesized by sintering a Cu-based metal–organic framework (Cu-MOF) embedded with exfoliated G. The G-embedded Cu-MOF was first synthesized by the self-assembly process of Cu(NO3)2·6H2O and DMTA (2,5-imethoxyterephthalatic acid) in the presence of exfoliated, few-layer G in the range of 2–5 μm. 5 wt% exfoliated G was incorporated into the MOF as an impurity. The X-Ray diffraction studies of the composite show that the characteristics of the few-layer G can be observed along with (hkl) lines of Cu-MOF. Upon heating, the Cu-MOF-G system decomposes to form a conductive composite consisting of sheet-like CuO and G sheets. Due to the ability of G to act as conductive additive, the CuO–G composite delivers improved electrochemical properties and stable cycling compared to pure CuO, the Cu-MOF or physically mixed Cu-MOF–G composites.