Question

electodes are made up of

Answer 1

$\huge\mathfrak\red{hey\:mate}$

Electrodes are made up of any metal

Answer 2

In a three-electrode cell, a counter electrode, also called an auxiliary electrode, is used only to make a connection to the electrolyte so that a current can be applied to the working electrode. The counter electrode is usually made of an inert material, such as a noble metal or graphite, to keep it from dissolving.