Abstract
Vanadium pentoxide gels have been obtained from decavanadic acid prepared by ion exchange on a resin from ammonium metavanadate solution. The progressive removal of water by solvent exchange in supercritical conditions led to the formation of high surface area V 2O 5, 1.6H 2O aerogels. Heat treatment under ammonia has been performed on these aerogels in the 450–900 °C temperature range. The oxide precursors and oxynitrides have been characterized by XRD, SEM, TGA, BET. Nitridation leads to divided oxynitride powders in which the fibrous structure of the aerogel is maintained. The use of both very low heating rates and high surface area aerogel precursors allows a higher rate and a lower threshold of nitridation than those reported in previous works. By adjusting the nitridation temperature, it has been possible to prepare oxynitrides with various nitrogen enrichment and vanadium valency states. Whatever the V(O,N) composition, the oxidation of the oxynitrides in air starts between 250 and 300 °C. This determines their potential use as chemical gas sensors at a maximum working temperature of 250 °C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
