Electrodeposition

The electrodeposition is a method which makes it possible either to cover an object with a lic layer Métal or to purify metals.

Metal electrodeposition

Before being able to deposit a metal, it will be necessary to study the behavior of this metal at the time of a electrolysis and in particular to trace a Courbe intensity-potential I=f (E). During the electrodeposition the desired reaction is done by reducing a metal Ion but it is necessary to be put under condition such as one does not reduce the Solvant.

Example of the Reduction of the Water

H₂O <==> H⁺ + OH^-

2:00 ⁺ + 2e^- - - > H₂

Thus always in the case of water, it is necessary that the release Hydrogène is with a Potentiel low than the potential of reduction of metal at the same time on the materials support but also on metal itself.

Example:

A metal M and its Ion corresponding Mⁿ⁺ to deposited on a compound C. the release Hydrogène is very low on the compound C and the potential of reduction of Mⁿ⁺ is higher the following reaction is done:

Mⁿ⁺+ N e^- - - > M

Metal settles on the other hand so on metal M the overpressure of the hydrogen release is weaker than the potential of reduction then all or part of the intensity east uses for the reduction of water

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