I have Au electrode and Fe electrode and connected with wire. Then, I immersed it to Au$+$ contained electrolyte. if so$,$ the Fe electrode is oxdized to Fe$2+$ and Au$+$ is reduced$($electroplated$)$ to Au electrode.

If I want to electroplate Au to Fe electrode should I need external emf? It seems I dont need emf because if Au electrode is oxidzed to Au$+$ and Au$+$ is reduced to Au on Fe electrode. The overall reaction is Au$($s$)->$Au$($s$).$ It seems i dont need emf.

If i need emf please tell me also how much emf is required.