To realize the fundamental difference between the bare graphene and Pt-modified graphene for Cu electrodeposition, we further study the heterogeneous interaction of the Cu atoms with different substrates using DFT. Adsorption free energy between substrates and Cu atoms and interaction energy between Cu-Cu adatoms are two factors to characterize the heterogeneous nucleation of Cu.(68) Three different systems were simulated (Figure ) using DFT. To evaluate the adsorption energy, we consider the following reaction mechanism, and the initial electrochemical adsorption step is given by: