Iridium(IV) oxide, often denoted as IrO2​, is a chemical compound composed of iridium (Ir) and oxygen (O) atoms. In this compound, iridium is in the +4 oxidation state.

Iridium(IV) oxide is a black or dark brown solid that is typically prepared through various chemical methods, often involving the oxidation of iridium compounds or iridium metal. It has applications in several areas due to its unique properties:

1. Catalysis: Iridium(IV) oxide is used as a catalyst in various chemical reactions, including oxidation and reduction processes. It’s particularly important in industrial applications like water electrolysis for hydrogen production, where it serves as an efficient catalyst for the oxygen evolution reaction.
2. Electrochemical Applications: Due to its catalytic properties, iridium(IV) oxide is used as an electrode material in electrochemical devices, such as in fuel cells and water-splitting technologies.
3. Biomedical Uses: Iridium(IV) oxide nanoparticles have shown promise in biomedical applications, including drug delivery and as contrast agents in imaging techniques.
4. Coatings and Electronics: Iridium(IV) oxide can be used in thin films and coatings for electronics and optical devices, owing to its electrical conductivity and stability.

It’s worth noting that iridium(IV) oxide is often prepared in a supported form, meaning it’s deposited onto a substrate or support material to enhance its stability and effectiveness as a catalyst or electrode material.