cobalt(II,III) oxide
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| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 452029756
| Name = Cobalt(II,III) oxide{{Cite web|url=https://www.sigmaaldrich.com/catalog/product/aldrich/203114|title=Cobalt(II,III) oxide 203114|website=Sigma-Aldrich}}
| ImageFile1 = Cobalt(II,III) oxide.jpg
| ImageSize1 =
| ImageName1 = Cobalt(II,III) oxide
| ImageFile2 = Cobalt(II,III)-oxide-unit-cell-2006-CM-perspective-3D-balls.png
| ImageSize2 =
| ImageName2 = Ball-and-stick model of the unit cell of Co3O4
| IUPACName = cobalt(II) dicobalt(III) oxide
| OtherNames = cobalt oxide, cobalt(II,III) oxide, cobaltosic oxide, tricobalt tetroxide
| Section1 = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 9826389
| InChI = 1/3Co.4O/rCo2O3.CoO/c3-1-5-2-4;1-2
| InChIKey = LBFUKZWYPLNNJC-PMPQCLQHAA
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/3Co.4O
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = LBFUKZWYPLNNJC-UHFFFAOYSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 1308-06-1
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = USK772NS56
| RTECS = GG2500000
| EINECS = 215-157-2
| PubChem = 11651651
| SMILES = [Co]=O.O=[Co]O[Co]=O
}}
| Section2 = {{Chembox Properties
| Formula = Co3O4
CoO.Co2O3
| MolarMass = 240.80 g/mol
| Appearance = black solid
| Density = 6.07 g/cm3{{RubberBible87th}}
| MeltingPtC = 895
| BoilingPtC = 900
| BoilingPt_notes = (decomposes)
| Solubility = Insoluble
| SolubleOther = soluble (with degradation) in acids and alkalis
| MagSus = +7380·10−6 cm3/mol
}}
| Section3 = {{Chembox Structure
| CrystalStruct = cubic
| SpaceGroup = Fd{{overline|3}}m, No. 227{{Cite web|url=https://materialsproject.org/materials/mp-18748/|title=mp-18748: Co3O4 (cubic, Fd-3m, 227)|website=materialsproject.org|access-date=2019-12-20}}
}}
| Section4 = {{Chembox Hazards
| GHSPictograms = {{GHS09}}{{GHS08}}
| GHSSignalWord = Danger
| HPhrases = {{H-phrases|317|334|350|411}}
| PPhrases = {{P-phrases|261|273|284|304+340|342+311}}
| NFPA-H = 2
| NFPA-F = 0
| NFPA-R = 0
| FlashPt =
| AutoignitionPt = }}
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Cobalt(II,III) oxide is an inorganic compound with the formula Co3O4. It is one of two well characterized cobalt oxides. It is a black antiferromagnetic solid. As a mixed valence compound, its formula is sometimes written as CoIICoIII2O4 and sometimes as CoO•Co2O3.{{Greenwood&Earnshaw2nd|page=1118}}
Structure
Co3O4 adopts the normal spinel structure, with Co2+ ions in tetrahedral interstices and Co3+ ions in the octahedral interstices of the cubic close-packed lattice of oxide anions.
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| 125px | 125px | 125px |
| tetrahedral coordination geometry of Co(II) | distorted octahedral coordination geometry of Co(III) | distorted tetrahedral coordination geometry of O |
Synthesis
Cobalt(II) oxide, CoO, converts to Co3O4 upon heating at around 600–700 °C in air. Above 900 °C, CoO is stable.Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1520. These reactions are described by the following equilibrium:
:2 Co3O4 {{eqm}} 6 CoO + O2
Applications
Cobalt(II,III) oxide is used as a blue coloring agent for pottery enamel and glass, as an alternative to cobalt(II) oxide.Frank Hamer, Janet Hamer (2004): [https://books.google.com/books?id=mhvlCeVL4dwC&pg=PA68 The Potter's Dictionary of Materials and Techniques]. University of Pennsylvania Press; 437 pp. {{ISBN|0812238109}}
Cobalt(II,III) oxide is used as an electrode in some lithium-ion batteries, possibly in the form of cobalt oxide nanoparticles.
Safety
Cobalt compounds are potentially poisonous in large amounts.[http://www.mallbaker.com/americas/msds/english/c4961_msds_us_default.pdf MSDS]{{dead link|date=August 2017 |bot=InternetArchiveBot |fix-attempted=yes }}