Table 1 Absorption bands observed in FT-IR spectra of the samples (OL overlapped).
Bands (cm−1) | ||||
|---|---|---|---|---|
MOF | LDH | LDH-COOH | LDH/MOF NC | Vibrational mode |
788 | 771 | 788 | \({\gamma} \text{CH}\) in aromatic rings | |
802 | 801 | 808 | Vibrations of phenyl rings | |
852 | 860 | 854 | \({\delta \text{CO}}({\text{COO}}^{-})\) | |
1124 | 1133 | 1130 | \({\delta \text{CH}}\) in aromatic rings | |
1412 | 1396 | \({{\vartheta }}_{\text{s}}\text{CO }({\text{COO}}^{-})\) in coordinated carboxylic acids | ||
1498 | 1491 | 1496 | Vibrations of phenyl rings | |
1585 | 1583 | \({{\vartheta }}_{\text{as}}\text{CO }({\text{COO}}^{-})\) in coordinated carboxylic acids | ||
1712 | 1572 | 1710 | \({{\vartheta }}_{\text{as}}\text{CO }({\text{COO}}^{-})\) in free carboxylic acids (pendent) | |
3000–3600 | 3000–3600 | 3000–3600 | Crystalline water and acidic OH of carboxylic groups | |
633 | 636 | ~ 633 (OL) | \({\vartheta }\) M–O, M–O–M and O–M–O; M=Co and Ni | |
1377–1383 | 1371–1398 | ~ 1377–1383 (OL) | Vibration of interlayer \({\text{NO}}_{3}^{-}\) and \({\text{CO}}_{3}^{2-}\) anions | |
1631 | 1630 | ~ 1631 (OL) | \({\delta \text{OH}}\) in water molecules | |
2856–2923 | 2871–2929 | ~ 2856–2923 (OL) | \({{\vartheta }}_{\text{s}}\text{CH}\) vibration (trace amount of EG) | |
3446 | ~ 3445 (OL) | ~ 3446 (OL) | \({\vartheta }\) M–OH vibration and interlayer water molecules | |
