University of South Africa, South Africa
Title: Gas Sensing Properties of VO2 –Vanadium Dioxide Nanobelts: Strongly Correlated Materials in Low Dimension
Biography: Aline Simo
Porous polycrystalline resistors made of metal oxides are highly demanded as semiconductor gas sensors. The operating at low temperature requires narrow band gap resistive gas sensors amongst which vanadium oxides have been found to be suitable for gas sensing materials. This is due to their ability to be used as catalysts in oxidation reaction and to form different lower oxides stoichiometry of the VO cubic lattice derived from V2O5. Hydrogen (H2) is one of the attractive energy sources to succeed the current carbon based energy, with the highest specific energy content of 141.79 MJ/kg and high risk of explosions while handling its storage and usage. In relation to H2 economy, various 1-D nanomaterials have been investigated as ideal candidates for gas sensing applications. Well established gas sensing materials such as SnO2, ZnO, WO3, have shown higher sensitivity and selectivity efficiency at high temperature resulting in significant power consumption with addition to their complexities in device integration. VO2 oxide nanobelts are demonstrated to be effective hydrogen gas sensors at room temperature with sensitivity as low as 14 ppm. The nanobelts (ultralong belt-like) nanostructures could be an ideal system for fully understanding dimensionally confined transport phenomena in functional oxides and for building functional devices based on individual nanobelts.