Question

Describe what is meant by an electrical double layer (EDL) that occurs at the interface between an electrode and the solution

Answer 1

A double layer (DL, also called an electrical double layer, EDL) is a structure that appears on the surface of an electrode when it is exposed to a solution. An electrical double layer (EDL) plays a major role in Understanding the interface between a charged surface and ionic liquids .The object might be a solid particle, a gas bubble, a liquid droplets or a porous body. The DL refers to two parallel layers of charge surrounding the electrode. The first layer, the surface charge (either positive or negative), comprises ions adsorbed onto the object due to chemical interactions. The second layer is composed of ions attracted to the surface charge via the coulomb force, electrically screening the first layer. This second layer is loosely associated with the electrode. It is made of free ions that move in the solution under the influence of electric attraction and thermal motion rather than being firmly attached. It is thus also called as the "diffuse layer".