# Copper plating with electrolyte not working (Cu(OH)2 vs CuSO4)

I've been experimenting using electroplating, and I recently made a solution by placing two copper pieces connected to a voltage source, in water. I suspect that this created copper(II) hydroxide, as it matches the color of that specific solution (green-blue) and doesn't stay dissolved in the water (it sinks to the bottom after a day).

A lot of people use copper(II) sulfate for an electrolyte during copper electrolysis, so I assumed $$\ce{Cu(OH)2}$$ would work the same, but if doesn't seem to be. A coin was attached to the negative wire, copper was attached to the positive wire, but attempting to copper plate a coin in this solution has failed.

Why is that? Both copper(II) hydroxide and sulfate have $$\ce{Cu^2+}$$. Shouldn't that be attracted to the negative wire, and append the copper to the desired item? Why does $$\ce{Cu(OH)2}$$ not behave like $$\ce{CuSO4}$$ during electrolysis?

I don't know too much about chemistry so if you explain it in simple terms, I would appreciate it!

• The current density on the plated electrode is low enough ( typically $$\pu{10 mA/cm^2}$$).