Table 1.

Observed bands in Fourier transform infrared analysis and related functional groups.

Band (cm−1)	Assigned or Associated	Reference
556 and 472	Metal oxygen (Fe–O)	[40]
1036	C–O	[10]
1277	C–N aromatic and aliphatic amines	[41]
1632	Carbonyl (–C=O) group stretching vibration	[42]
2362	CH stretching	[43]
2926	Asymmetric stretching of C–H	[44]
3426	N–H stretching vibration of group NH2 and O–H	[42,45]