electrolysis doesnt necessary use the same material for both electrodes.
such an example will be the industrial electrolysis of brine for manufacturing of chlorine gas. the anode (where chlorine is formed) is made from graphite and the cathode (where sodium forms) is mercury.
the sodium formed will dissolve in mercury to form sodium amalgam. sodium is removed frm the amalgam by reacting with water. Mercury is recovered in the process. The reaction is as below:
NaHg + 2H2O -> NaOH + H2 + Hg