I am using NiSO4 aqueous solution, Pt anode, Cu cathode coated with Au for Ni electroplating (at 3 V DC) on Au. Cu is not exposed to solution. To calculate cell potential should I consider Cu/Pt or Au/Pt. If I replace Pt with graphite, whether for same 3 V DC supply Ni plating would be possible? Your suggestion will be very useful.