Table 2.
Evolution of electrochemical parameters from Tafel’s estimation and Electrochemical impedance spectroscopy modeling. Ecorr: Corrosion potential, Icorr: corrosion current, Rs: Solution resistance Rp: Polarization resistance, Cdl: Capacitance, Eq=0: open circuit potential
| Material | Electrochemical Parameters | |||||
|---|---|---|---|---|---|---|
| Tafel’s estimation | EIS parameters | |||||
| Sample | Ecorr /V (vs. SCE) |
Icorr (μA/cm2) |
Rs (Ω) | Rp – (MΩ/ cm2) |
Cdl-(μF/ cm2) |
Chi-squared values (average) |
| Bulk-like (HC) | −0.540 ± .244 |
0.29 ± 0.46 | 68.77 ± 1.70 |
4.57 ± 2.07 |
10.90 ± 0.33 |
0.001 |
| Nano- crystalline (HC) |
−0.751 ± .011 |
1.86 ± 0.21 | 66.21 ± 0.15 |
4.01 ± 0.94 |
19.21 ± 0.79 |
0.002 |
| Tribolayer (HC) |
−0.729 ± .011 |
0.76 ± 0.09 | 71.83 ± 1.23 |
2.39 ± 0.60 |
15.20 ± 0.75 |
0.001 |
| Bulk-like (LC) | −0.706 ± .022 |
0.17 ± 0.12 | 73.04 ± 1.79 |
7.86 ± 1.58 |
12.10 ± 4.20 |
0.001 |
| Nano- crystalline (LC) |
−0.741 ± .013 |
2.49 ± 0.46 | 66.93 ± 1.29 |
3.50 ± 0.76 |
18.20 ± 2.00 |
0.002 |
| Tribolayer (LC) |
−0.729 ± .018 |
0.77 ± 0.17 | 70.56 ± 0.72 |
2.86 ± 0.44 |
17.00 ± 1.80 |
0.001 |
HC: high carbon, LC: low carbon, Ecorr: Corrosion potential, Icorr: corrosion current, Rs: Solution resistance, Rp: Polarization resistance, Cdl: Capacitance