In this study, graphene-coated nickel foam (GNF) is discovered unprecedentedly to have significant catalytic effect on electrodeless metal (M: Au, Pt, Ag, and Cu) deposition on the graphene without any extra reducing agent because of electron transfer from interface electric double layer (EDL) induced by graphene on the nickel surface. Although the EDL model is experimentally and theoretically confirmed by work function and density functional theory (DFT) calculation, it is for the first time experimentally proved in this work. The interface EDL catalytic mechanism reveals the electron communication between graphene and nickel metal, and supports the catalytic function as an “electron bump” to accelerate the electron transfer in the metal redox reaction. In addition, the concomitant phenomenon of simultaneous formation of Ni(OH)2 nanosheets is also elucidated. Ni(OH)2-wrapped Ag hybrid developed on the GNF (Ag@Ni(OH)2-GNF) is found to serve as an efficient binder-free electrochemical sensor because of its unique structure. It is believed that the interesting EDL catalytic mechanism will contribute to more extensive and important applications in other fields such as oxygen reduction and hydrogen evolution reactions and Li ion battery.