As stated in the previous research, the Pt-nanoparticles modification on the working electrode can enhance the uniformity and durability of the reversible metal electrodeposition. The morphologies of electrodeposited Cu film on the bare graphene and Pt-modified substrate were characterized by SEM (Figure ). On the bare graphene substrate, Cu tends to become sparsely distributed large particles due to the high surface energy between graphene and metallic Cu (Figure ).