Physicochemical characterisation of nanosized V/Fe 2 O 3 reaction products

Abstract

Nanosized vanadium metal and iron oxide (Fe₂O₃) powder with a purity of 99 ± % were mixed in the stoichiometric ratio. Powder specimens were fired in a tube furnace at 350–930°C for l h in Ar atmosphere. This is considered as a thermit reaction involving an oxidation reduction reaction of a metal reacting with a metallic oxide to form a more stable oxide and the corresponding metal. The reaction products were characterised using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, and the magnetic behaviour was measured using vibrating sample magnetometer. Also the catalytic decomposition of CO₂ was applied on the fired samples at 300–500°C. Reduction of iron oxide Fe₂O₃ takes place at 930°C with the formation of the magnetite, wüstite, metallic iron and orthovanadate FeVO₄ phases in nanocrystalline size of ∼92 nm with characterised diluted magnetic properties. This fired products showed a catalytic activity towards CO₂ decomposition with the formation of single and multiwalled carbon nanotubes with average diameter 80–100 nm respectively.