Vanadium(IV) oxide
Vanadium(IV) oxide or vanadium dioxide is an inorganic compound with the formula VO2. It is a dark blue solid. Vanadium(IV) dioxide is amphoteric, dissolving in non-oxidising acids to give the blue vanadyl ion, [VO]2+ and in alkali to give the brown [V4O9]2− ion, or at high pH [VO4]4−. VO2 has a phase transition very close to room temperature (~68 °C (341 K)). Electrical resistivity, opacity, etc, can change up several orders. Owing to these properties, it has been used in surface coating, sensors, and imaging. Potential applications include use in memory devices, phase-change switches, passive radiative cooling applications, such as smart windows and roofs, that cool or warm depending on temperature, aerospace communication systems and neuromorphic computing.
| Names | |
|---|---|
| IUPAC name
Vanadium(IV) oxide | |
| Other names
Vanadium dioxide Divanadium tetroxide | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.031.661 |
| EC Number |
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| 873472 | |
PubChem CID |
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CompTox Dashboard (EPA) |
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| Properties | |
| VO2 | |
| Molar mass | 82.94 g/mol |
| Appearance | Blue-black powder |
| Density | 4.571 g/cm3 (monoclinic) 4.653 g/cm3 (tetragonal) |
| Melting point | 1,967 °C (2,240 K) |
| +99.0·10−6 cm3/mol | |
| Structure | |
| Distorted rutile (<70 °C (343 K), monoclinic) Rutile (>70 °C (343 K), tetragonal) | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
toxic |
| GHS labelling: | |
| Warning | |
| H315, H319 | |
| P264, P280, P302+P352, P305+P351+P338, P332+P313, P337+P313, P362 | |
| NFPA 704 (fire diamond) | |
| Flash point | Non-flammable |
| Related compounds | |
Other anions |
Vanadium disulfide Vanadium diselenide Vanadium ditelluride |
Other cations |
Niobium(IV) oxide Tantalum(IV) oxide |
| Vanadium(II) oxide Vanadium(III) oxide Vanadium(V) oxide | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references | |