The discussion about electrode assembly and titanium anodes has taken over the electromagnetic space. Now, it seems like every professional has a thing or two to say about electrodes. But for people who have little or no science orientation, even the concept of electrodes is a bit vague to them. So it is only right that we first try to understand what electrodes mean before we talk about the complex terms. Electrode refers to any material that allows electrons to pass through it. Electrons are the elements that are responsible for electricity. The positive electrode is known as an anode, while the negative is referred to as a cathode.
The first type of Electrode was introduced into the world by scientist Johan Wilcke. The first electrode was known as an electrophore. To visualize the electrodes, think of a battery with positive and negative signs. The negative sign is the cathode indicating that current leaves through there, and the positive side of the anode, is the exact opposite. Majorly, there are two types of electrodes recognized: the inert and the reactive one. As the name implies, the inert electrode doesn’t react, while the reactive reacts. Examples of reactive electrodes include copper, silver, zinc, etc. On the other hand, examples of inert electrodes include; gold, rhodium, and platinum.
Aside from the major classes of electrodes, there are some other types of electrodes. Let’s take a close look at these types – they include;
The redox type of Electrode is the most uncommon type of Electrode because it depends on the redox potential coming from the metal. In this type of electrode, the mix is dependent on a metal that does not react efficiently. Since the metal is inert, it can not form an electrode on its own. To achieve this electrode state, it undergoes oxidation. The inert metal is mixed with an ion solution of a metal. The solution will contain ions that have double oxidation states. Because the ions are in different oxidations, there is a high chance for these ions to accept or lose electrons. This phenomenon is usually referred to as the redox potentials of the ions. This redox potential depends on how concentrated each ion is.
As the name implies, a gas electrode depends on gas and, of course, the metal to get formed. The examples of the gasses used in gas electrodes are chlorine, hydrogen, and oxygen. To form this gas electrode, the gas mixes in a solution that contains the ions of the gas. For example, a hydrogen gas electrode will form when there is a H± ion in the solution, while the chlorine gas electrode will form when there is a Cl- ion in the solution. As with any chemical reaction, the ion concentration in the solution will act as a catalyst for the reaction. Also, if there is some pressure within the gas, it will also speed up the gas reaction. Mostly, for gas electrodes, an inert metal like platinum is usually used.
Apart from the types of electrodes discussed in this guide, some other electrodes are not exactly common. They include metal to metal electrodes and the metal to salt electrodes.