A novel method to synthesize submicrometer vanadium carbide by temperature programmed reaction from vanadium pentoxide and phenolic resin. (January 2017)

• Record Type: Journal Article
• Authors: Wu, Yue-Dong; Zhang, Guo-Hua; Chou, Kuo-Chih
• Is Part Of: International journal of refractory metals & hard materials. Volume 62(2017)Part A
• Page Start: 64
• Page End: 69
• Publication Date: 2017-01
• Subjects: Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2016.10.020
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: Submicrometer vanadium carbide (V8 C7 ) can be synthesized from V2 O5 encapsulated in phenol resin. The precursor powders were produced by coating V2 O5 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 V2 O5 . 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 V2 O5 are V2 O5 → VO2 → V2 O3 → V6 C5 → V8 C7 . The single phase of V8 C7 can be prepared as the molar ratio of V2 O5 to phenol resin is 1:1.2 at the temperature higher than 1373 K. The prepared V8 C7 particles are about 300 nm in size. Highlights: V8 C7 was synthesized roasting V2 O5 encapsulated in phenol resin. V8 C7 particles have uniform size of about 300 nm. Phase evolution sequences are V2 O5 → VO2 → V2 O3 → V6 C5 → V8 C7.