Iridiumoxid

Iridium oxide, often written as iridium oxide or IrO2 in its best-known form, is an inorganic compound of iridium and oxygen. The term Iridiumoxid can refer to several oxides of iridium, but IrO2 (iridium(IV) oxide) is the most widely encountered and remains the principal oxide in commercial and research contexts. Other oxides, such as IrO3 and IrO4, have been prepared under strong oxidizing conditions or in complex solid-state syntheses, but they are less common and typically less stable under ambient conditions.

IrO2 has a rutile-type crystal structure and a high melting point. It is dense, hard, and chemically very stable, with notable resistance to corrosion in acidic media. The material conducts electricity and can form durable thin films or coatings.

Preparation methods include direct oxidation of metallic iridium at high temperatures, precipitation from iridium salts followed by thermal treatment, and electrodeposition to form IrO2 coatings. Iridium oxides may also be produced by sol-gel or hydrolysis routes to yield nanostructured powders or films.

Applications center on its performance as an electrochemical and protective material. Iridium oxide compounds, especially thin films of IrOx, are used as durable, biocompatible electrode coatings with high charge-injection capacity, notably in neural stimulation devices and biosensors. IrO2 and related oxides are also employed as electrocatalysts for the oxygen evolution reaction in acidic electrolytes and for chlorine evolution in electrolysis, as well as protective coatings for harsh environments.

Safety notes: iridium compounds are generally of low to moderate toxicity; handling should follow standard laboratory precautions for metal oxides.