Opuntia ficus-indica Extract as Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution

Table 4

Characteristic peaks obtained from FT-IR spectra for 1.0 M HCl + Opuntia ficus-indica solution before and after corrosion test.

1.0 M HCl + 300 ppm inhibitor before corrosion test		1.0 M HCl + 300 ppm inhibitor after corrosion test
Frequency (cm^−1)	Functional group and vibration type	Frequency (cm^−1)	Functional group and vibration type
3118	N-H stretch	3368–3369	N-H stretch
3018	O-H stretch	3189	O-H stretch
1720	C=O stretch	1610	C=O stretch
1627	N-H bending	1588	N-H bending
1394	C-H bending	1394	C-H bending
1222	C-N stretch	1222	C-N stretch
1074	C-O stretch	1074	C-O stretch