While doing electroplating of Copper as a project I found the Cathode is depositing with a Black material.Why?

Question

I used copper sulphate solution as electrolyte and then tried with Sodium chloride and dilute acids .All cases in place of copper I found black material is depositing on cathode.any one suggest a good electrolyte for copper plating?

Answer 1

Well, I do not quite understand what you did. What do you mean "then tried with Sodium chloride and dilute acids"? Please put forward details. anyway, since the reduction potential of C++ is greater than H+, even if you simply put a piece of iron nail into CuSO4 solution---Cu metal will begin to deposit on it and this iron nail would look like a piece of copper nail.
I am not sure if your set up is correct:
The anode and cathode in the electroplating cell are connected to an external supply of direct current, a battery or, more commonly, a rectifier. The anode is connected to the positive terminal of the supply, and the cathode (article to be plated) is connected to the negative terminal. When the external power supply is switched on, the metal at the anode is oxidized from the zero valence state to form cations with a positive charge. These cations associate with the anions in the solution. The cations are reduced at the cathode to deposit in the metallic, zero valence state.