Chemical compound

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.[4]

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.[4]

Cobalt(II,III)-oxide-xtal-2006-Co(II)-coord-CM-3D-balls.png Cobalt(II,III)-oxide-xtal-2006-Co(III)-coord-CM-3D-balls.png Cobalt(II,III)-oxide-xtal-2006-O-coord-CM-3D-balls.png
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.[4] Above 900 °C, CoO is stable.[4][5] These reaction are described by the following equilibrium:

2 Co3O4 ⇌ 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.[6]

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.[7]

See also

References

  1. ^ "Cobalt(II,III) oxide 203114". Sigma-Aldrich.
  2. ^ Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
  3. ^ "mp-18748: Co3O4 (cubic, Fd-3m, 227)". materialsproject.org. Retrieved 2019-12-20.
  4. ^ a b c d Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 1118. ISBN 978-0-08-037941-8.
  5. ^ Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1520.
  6. ^ Frank Hamer, Janet Hamer (2004): The Potter's Dictionary of Materials and Techniques. University of Pennsylvania Press; 437 pp. ISBN 0812238109
  7. ^ MSDS[permanent dead link]