Table 1 FTIR analysis of Padina sp. aqueous extract, 0.01 M of silver nitrate (AgNO3) solution, and silver nanoparticles synthesized by the reduction of 0.01 M silver nitrate with the Padina sp. aqueous extract
| Padina sp. aqueous extract | 0.01 M of silver nitrate (AgNO3) solution | Silver nanoparticles (AgNPs) synthesized | ||||||
|---|---|---|---|---|---|---|---|---|
| Frequency (cm−1) | Bond/stretching | Functional groups | Frequency (cm−1) | Bond/stretching | Functional groups | Frequency (cm−1) | Bond/stretching | Functional groups |
| 3350.07 | N–H stretch, O–H stretch, H-bonded | 1°,2° amines, amides, carboxyl, phenols | 3350.24 | N–H stretch, O–H stretch, H-bonded | 1°,2° amines, amides, alcohols, phenols | 3422.00 | O–H stretch, H-bonded | Alcohols, phenols |
| 2123.39 | –C≡C– stretch | alkynes | 2124.36 | –C ≡ C– stretch | alkynes | 2921.02 | C-H stretch | alkanes |
| 1637.74 | N–H bend | 1° amines | 1635.83 | N–H bend | 1° amines | 1610.46 | N–H bend | 1° amines |
| 1329.82 | N–O symmetric stretch | Nitro compounds | 1337.47 | N–O symmetric stretch | nitro compounds | 1384.27 | –NO2 (aliphatic) or C–H (plane bend) | nitro groups or alkenes |
| 1106.90 | C–N stretch | aliphatic amines | 1181.13 | C–H wag (–CH2X) | alkyl halides | 1023.91 | C–N stretch | aliphatic amines |