Table 2 Electrochemical impedance parameters for copper plates in 1 M HCl solution in the absence and presence of different concentrations of the pyrazolylindolenine compounds
From: Corrosion inhibition properties of pyrazolylindolenine compounds on copper surface in acidic media
|  | Conc. Inhib. (mM) | Ecorr.(mV) | Icorr.(A cm-2) | βc(mV/dec) | βa(mV/dec) | Rp(Ω cm-2) | CR(mm/y) | η% | Kads.(mol-1) | ΔG(kJ mol-1) | θ |
|---|---|---|---|---|---|---|---|---|---|---|---|
Blank | 0.0 | 0.6 | 19×10-4 | 184 | 144 | 368 | 4.694 | - | - | - | - |
InPzTAm | 0.5 | 0.300 | 3.2×10-4 | 187 | 114 | 290 | 3.7 | 21.1 | 2.74×10-4 | −6225 | 0.212 |
|  | 1.0 | 0.013 | 3.7×10-5 | 132 | 125 | 190 | 0.43 | 90.8 | 9.9×10-3 | −15633 | 0.909 |
|  | 1.5 | 0.011 | 2.8×10-5 | 107 | 74 | 120 | 0.34 | 92.7 | 12.7×10-3 | −32501 | 0.928 |
|  | 2.0 | 0.008 | 2.4×10-5 | 64 | 72 | 81 | 0.28 | 94.0 | 15.7×10-3 | −33552 | 0.940 |
|  | 2.5 | 0.01 | 1.6×10-5 | 87 | 44 | 99 | 0.19 | 95.9 | 23.4×10-3 | −44394 | 0.960 |
InPzTH | 1.0 | 0.015 | 4.3×10-5 | 218 | 215 | 470 | 0.49 | 89.5 | 8.58×10-3 | −15279 | 0.896 |
|  | 1.5 | 0.02 | 5.8×10-6 | 95 | 138 | 970 | 0.67 | 85.7 | 6.01×10-3 | −21595 | 0.857 |
|  | 2.0 | 0.024 | 2.3×10-6 | 101 | 129 | 1420 | 0.40 | 91.4 | 10.73×10-3 | −31666 | 0.915 |
|  | 2.5 | 0.034 | 1.7×10-6 | 98 | 121 | 2900 | 0.21 | 95.3 | 20.33×10-3 | −43542 | 0.953 |
InPzPh | 1.0 | 0.015 | 7.0×10-5 | 193 | 89 | 100 | 3.12 | 33.9 | 0.51×10-3 | −8235 | 0.340 |
|  | 2.0 | 0.010 | 5.8×10-5 | 127 | 89 | 84 | 0.97 | 79.3 | 3.84×10-3 | −26573 | 0.794 |
|  | 3.0 | 0.002 | 3.3×10-5 | 115 | 64 | 97 | 0.78 | 83.3 | 5.02×10-3 | −41852 | 0.834 |
|  | 4.0 | 0.006 | 1.9×10-5 | 142 | 63 | 210 | 0.72 | 84.6 | 5.52×10-3 | −56744 | 0.847 |