A novel method to synthesize submicrometer vanadium carbide by temperature programmed reaction from vanadium pentoxide and phenolic resin

- V8C7 was synthesized roasting V2O5 encapsulated in phenol resin.
- V8C7 particles have uniform size of about 300 nm.
- Phase evolution sequences are V2O5 → VO2 → V2O3 → V6C5 → V8C7.

Submicrometer vanadium carbide (V8C7) can be synthesized from V2O5 encapsulated in phenol resin. The precursor powders were produced by coating V2O5 powders with phenolic resin shells. Then the precursor powders were roasted at various temperatures from 1173 K to 1473 K for 2 h in a flowing Ar atmosphere. The decomposed carbon from phenolic resin could be used to reduce V2O5. The samples obtained with different conditions were characterized by X-ray diffraction (XRD), Field-emission scanning electron microscope (FE-SEM), Transmission Electron Microscope (TEM), and Energy Disperse Spectroscopy (EDS). The results show that phase evolution sequences from V2O5 are V2O5 → VO2 → V2O3 → V6C5 → V8C7. The single phase of V8C7 can be prepared as the molar ratio of V2O5 to phenol resin is 1:1.2 at the temperature higher than 1373 K. The prepared V8C7 particles are about 300 nm in size.