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Tafel curve of copper electrode

The half-cell reaction for copper is:

Cu2+ + 2e- → Cu ; Eo = +0.34V

The exchange current density is io = 1 A m-2

For the Tafel equation:

\[\eqalign{ & \eta = a + b\log \left( i \right) \cr & {\rm{ }} = a + b\log \left( {{i \over {{i_o}}}} \right) \cr} \]

The Tafel slope is given by:

\[b = \pm 2.303\left( {{{RT} \over {\alpha ZF}}} \right)\]

Taking:
T = 300 K
α = 0.5
Z = 2

We get:
bA = 0.059 V/decade of current
and
bC = -0.059 V/decade of current

For the anodic curve: ηA = EAEo
EA = Eo + ηA

For the cathodic curve: ηC = ECEo
EC = Eo + ηC


The plot of this is shown on the diagram below: