Despite the scarcity and cost of iridium oxide, it is still the material of choice in numerous fields of science and applications, including capacitors, electrochromism, sensors, and various oxidation electrocatalysis (e.g., chlorine evolution reaction, detoxification, and oxygen evolution reaction). Such versatility is attributed to the distinct features of iridium oxides, such as their activity, biocompatibility, conductivity, and durability. The features and properties of iridium oxides are strongly dependent on the fabrication method. In this review, methodologies relating to the synthesis and fabrication of solid-state iridium oxides have been thoroughly collected and discussed. Structuring and crystallization techniques for iridium oxides are also noted. At the end of the review, the effects of utilizing a certain fabrication method on the characteristics of the iridium oxide product are recapitulated, together with the recommended application of the product in various fields.
