Iridium(IV) oxide, IrO
2, is the only well-characterised oxide of iridium. It is a blue-black solid. The compound adopts the TiO
2 rutile structure
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite.
Rutile has one of the highest refractive indices at visible ...
, featuring six coordinate iridium and three coordinate oxygen.
It is used with other rare oxides in the coating of anode-electrodes for industrial electrolysis and in
microelectrode
A microelectrode is an electrode used in electrophysiology either for recording neural signals or for the electrical stimulation of nervous tissue (they were first developed by Ida Hyde in 1921). Pulled glass pipettes with tip diameters of 0. ...
s for
research.
As described by its discoverers, it can be formed by treating the green form of
iridium trichloride with oxygen at high temperatures:
:2 IrCl
3 + 2 O
2 → 2 IrO
2 + 3 Cl
2
A hydrated form is also known.
Application
Iridium dioxide can be used as an anode electrode for industrial electrolysis and as a microelectrode for electrophysiological studies.
Iridium dioxide can be used to make coated electrodes.
References
Iridium compounds
Transition metal oxides
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