Binding energy of Ti 2p and O 1s core levels in different compounds with relative peak area percentage.
| Sample | Ti species | Ti 2p3/2 binding energy (eV) | Relative peak area (%) | O species | O binding energy (eV) | Relative peak area (%) |
|---|---|---|---|---|---|---|
| Ti substrate before etching | Ti0 | 454.1 | 20.5 | Oxide | 530.0 | 54.6 |
| Ti4+ | 458.4 | 79.5 | OH− | 531.1 | 25.7 | |
| Adsorbed H2O | 532.1 | 19.7 | ||||
| Ti substrate after etching | Ti0 | 454.2 | 100 | Oxide | 530.0 | 31.4 |
| OH− | 530.8 | 63.3 | ||||
| Adsorbed H2O | 532.8 | 5.3 | ||||
| Microspikes before etching | Ti4+ | 458.7 | 100 | Oxide | 530.3 | 77.3 |
| OH− | 531.1 | 12.4 | ||||
| Adsorbed H2O | 532.3 | 10.3 | ||||
| Microspikes after etching | Ti0 | 454.2 | 30 | Oxide | 530.1 | 44.4 |
| TixOy (Ti3+/Ti2+) | 456.3 | 27 | OH−/defects | 531.5 | 35.1 | |
| Ti4+ | 458.2 | 43 | Adsorbed H2O | 532.2 | 19.5 |