Nondestructive covalent functionalization of carbon nanotubes by selective oxidation of the original defects with K2FeO4

- Nondestructive covalent CNT functionalization is realized by defect oxidation.
- A green oxidant K2FeVIO4 is used for CNT oxidation for the first time.
- Effective CNT oxidation can be achieved at 60 °C in 3 h.
- Oxidized CNTs are obtained in yields of above 100 wt%.
- FeO3, an unusual Fe (VI) specie, is produced when K2FeO4 is dissolved in H2SO4.