Table 2. FTIR Peaks (cm–1) and Functional Groups in Biocharsa.
| wave number range cm–1 | functional groups | SBB biochar | PSB | SBB-KOH | PSB-KOH |
|---|---|---|---|---|---|
| 3220–3600 | –OHNP | 3361.93 (−OHNP) | 3385 (−OHNP) | 3375 (−OHNP) | |
| 3000–4000 | –OH | 3780.48 (−OH) | 3826.77 (−OH) | 3780.48 (−OH) | 3178.69 (−OH) |
| 2500–3300 | –COOH | 3014.74 (−COOH) | |||
| 1670–1820 | –C=O, – CO32− | 1707 (−C=O, – CO32−) | 1697.36 (−C=O, – CO32−) | 1697 (−C=O, – CO32−) | |
| 1550–1650 | –N=H | 1586.2 (−N=H) | 1577 (−N=H) | 1558.48 (−N=H) | |
| 1430–1490 | –CH2 | 1375.25 (−CH2) | 1369.46 (−CH2) | 1363.67 (−CH2) | |
| 1000–1095 | =C–H | 1080.14 (=C–H) | 1112.93 (=C–H) | 1004.91 (=C–H) | |
| 800–700 | –C–Ha | 754.17 (−C–Ha) | 779.24 (−C−Ha) | 825.53 (−C–Ha) | |
| 800–700 | –C–Br | 773.46 (−C–Br) | |||
| 600–500 | –C–I | 615.29 (−C–I) |
a
A: Aromatic; NP: nonpolymeric; M: metal; SBB: sugar cane bagasse biochar; PSB: paddy straw biochar; SBB-KOH: sugar cane bagasse biochar (KOH activated); PSB-KOH: paddy straw biochar (KOH activated).