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Nernst Equation
E(eq)=E(o)+(RT/nf)ln[Red/Ox]
Thermodynamic Equilibrium
i=0
Fast Slow
Butler-Volmer/Tafel Equations
Current Flow
i
Static Potential (Faradaic)
Fast
Nernst + Diffusion
Slow
Butler-Volmer/Tafel
Faradaic Non-faradaic
CAPACITIVE
Dynamic Potential
Controlled Potential
Cottrell Plot
y = 0.0755x - 0.0166
R2 = 0.9945
-0.050
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.000 1.000 2.000 3.000 4.000 5.000 6.000
Time ^ -1/2
Current
Double Step Chronoamperometry
N
N
W
CO
OC CO
CO
W(CO)4bpy
bpy=2,2’bipyridine
Bpy *
t2g
eg(*)
d-orbitals on tungsten
Think like an inorganic chemist!
Bpy *
t2g
eg(*)
e–
Bpy *
t2g
eg(*)
Current-Potential-Time Space
t
E
i
E
1/2
Reversible System
Potential
Time
Current
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