Potentiodynamic polarization parameters of mild steel in 1 M HCl solution without and with different concentrations of l-histidine and LHIL.

C (mM)	E corr (mV)	i corr (μA cm−2)	β a (mV dec−1)	β c (mV dec−1)	η	θ
Blank	−382	2070	108	−138	—	—
l -Histidine
0.5	−379	1550	103	−135	25.0	0.25
1	−377	1310	97	−132	36.5	0.365
2	−385	1010	95	−133	51.1	0.511
LHIL
0.5	−386	977.2	104	−136	52.8	0.528
1	−421	426.4	116	−135	79.4	0.794
2	−445	22.91	64	−143	98.8	0.988