Samples | O (at%) | N (at%) | C-O (at%) | C=O (at%) | O-C=O (at%) |
H700 | 12.2 | 1.4 | 5.1 | 4.5 | 3.2 |
H800 | 10.5 | 0.8 | 3.3 | 1.9 | 1.1 |
H900 | 6.6 | 0.4 | 1.2 | 0.6 | 0.4 |