A Comparative Study of the Inhibitory Effect of the Extracts of Ocimum sanctum, Aegle marmelos, and Solanum trilobatum on the Corrosion of Mild Steel in Hydrochloric Acid Medium

Table 3

Potentiodynamic polarization parameters for mild steel in 1N HCl containing various concentrations of the plant extracts.

Name of the plant extract	Conc. of extract (% in v/v)	𝐸corr (V)	𝐼corr (mA/cm^2)	Tafel slope mV/decade		Inhibition efficiency (%)
				𝑏𝑎	𝑏𝑐
Blank	—	−0.510	3.57	78	122	—
Ocimum sanctum	2.0	−0.515	0.24	74	126	93.3
	4.0	−0.498	0.12	76	124	96.6
	6.0	−0.496	0.01	74	124	99.7
	8.0	−0.499	0.09	74	122	97.5
	10.0	−0.500	0.12	76	124	96.6
Aegle marmelos	2.0	−0.493	0.40	78	126	88.5
	4.0	−0.492	0.31	76	124	91.3
	6.0	−0.497	0.21	74	122	94.1
	8.0	−0.483	0.09	74	122	97.5
	10.0	−0.492	0.09	76	124	97.5
Solanum trilobatum	2.0	−0.490	1.45	74	126	59.4
	4.0	−0.480	0.97	76	128	72.8
	6.0	−0.462	0.75	74	126	79.0
	8.0	−0.459	0.56	78	130	84.3
	10.0	−0.460	0.33	76	128	90.8