Nanostructured Iridium Oxide: State of the Art

Abstract

Iridium Oxide (IrO2) is a metal oxide with a rutile crystalline structure, analogous to the TiO2 rutile polymorph. Unlike other oxides of transition metals, IrO2 shows a metallic type conductivity and displays a low surface work function. IrO2 is also characterized by a high chemical stability. These highly desirable properties make IrO2 a rightful candidate for specific applications. Furthermore, IrO2 can be synthesized in the form of a wide variety of nanostructures ranging from nanopowder, nanosheets, nanotubes, nanorods, nanowires, and nanoporous thin films. IrO2 nanostructuration, which allows its attractive intrinsic properties to be enhanced, can therefore be exploited according to the pursued application. Indeed, IrO2 nanostructures have shown utility in fields that span from electrocatalysis, electrochromic devices, sensors, fuel cell and supercapacitors. After a brief description of the IrO2 structure and properties, the present review will describe the main employed synthetic methodologies that are followed to prepare selectively the various types of nanostructures, highlighting in each case the advantages brought by the nanostructuration illustrating their performances and applications.

Improving the Oxygen Evolution Activity and Stability of Nb-Doped TiO2-Supported RuO2 by a SnO2 Interlayer: A Model Catalyst Study on Single-Crystal Oxide Heterostructures

“…Hence, the decrease in R e upon introducing the SnO 2 interlayer can explain the enhanced OER activity. Considering the reported work functions of bulk RuO 2 (5.2 eV) and electron affinity of n-type TiO 2 (4.0 eV), the interfaces of RuO 2 /TiO 2 form a Schottky barrier, resulting in a high electronic resistance at the interface. By contrast, an n–n junction is formed at the SnO 2 interlayer/Nb:TiO 2 -substrate interface because the electron affinity of n-type SnO 2 is 4.5 eV, which is higher than that of TiO 2 .…”

Recent progress on topological semimetal IrO2: electronic structures, synthesis, and transport properties

“…Since we attempt to focus on the fundamental condensed matter and materials physics, the electrochemical-related properties of IrO 2 and its potential applications in electrocatalysis, electrochromic devices, chemical sensors, etc are not discussed. There are several recent review articles in these areas [55][56][57][58][59] that we encourage the readers to consult.…”

Extending the Lifetime of pH Microelectrode with Stabilized Palladium Hydride

“…29 Among them, metal/metal oxides have received great attention. 30 RuO 2 , 31 IrO 2 , 32,33 TiO 2 , 34 SnO 2 , 35 and the mixed oxide systems [36][37][38] have been widely reported because of their fast potentiometric response, and good stability. However, many challenges remain regarding the fabrication of micrometer size sensors.…”