Low-Cost and Facile Synthesis of the Vanadium Oxides V₂O₃, VO₂, and V₂O₅and Their Magnetic, Thermochromic and Electrochromic Properties

Abstract

In this study, vanadium sesquioxide (V₂O₃), dioxide (VO₂), and pentoxide (V₂O₅) were all synthesized from a single polyol route through the precipitation of an intermediate precursor: vanadium ethylene glycolate (VEG). Various annealing treatments of the VEG precursor, under controlled atmosphere and temperature, led to the successful synthesis of the three pure oxides, with sub-micrometer crystallite size. To the best of our knowledge, the synthesis of the three oxides V₂O₅, VO₂, and V₂O₃ from a single polyol batch has never been reported in the literature. In a second part of the study, the potentialities brought about by the successful preparation of sub-micrometer V₂O₅, VO₂, and V₂O₃ are illustrated by the characterization of the electrochromic properties of V₂O₅ films, a discussion about the metal to insulator transition of VO₂ on the basis of in situ measurements versus temperature of its electrical and optical properties, and the characterization of the magnetic transition of V₂O₃ powder from SQUID measurements. For the latter compound, the influence of the crystallite size on the magnetic properties is discussed.