Marjoram Extract as Corrosion Inhibitor for Dissolution of Zinc in 1.0 M HCl

Table 3

Electrochemical parameters for zinc in absence and presence of different concentrations of Marjoram extract in 1.0 M HCl solution at 30°C obtained from Tafel polarization curves.

Inhibitor concentration (ppm)	−E corr (mV SCE)	𝑏𝑎 (V dec^−1)	𝑏𝑐 (V dec^−1)	𝐼corr (mA cm^−2)	Θ	IE (%)
HCl (1 M)	996	0.43	0.49	2.41	—	—
100	989	0.56	0.56	0.93	0.61	61.40
200	985	0.63	0.60	0.65	0.73	73.00
300	978	0.71	0.68	0.47	0.80	80.50
400	976	0.80	0.73	0.24	0.90	90.00
500	974	0.86	0.79	0.18	0.92	92.50