Electrolysis of copper sulphate solution using copper electrodes
When copper electrodes are used the action at the cathode is exactly the same as with platinum or carbon electrodes. Cu2+ ions are discharged and deposited on the cathode.
At the anode, however, copper ions go into solution in preference to the discharge of either OH – or S042 – ions.
As the electrolysis continues, the cathode increases in thickness while the anode slowly dissolves away. The concentration of copper sulphate in the electrolyte remains constant, and the action ceases when the anode is completely dissolved away.