Abstract

Stable blue suspensions of 2 nm diameter iridium oxide (IrOx·nH2O) nanoparticles were obtained by hydrolyzing IrCl62− in base at 90 °C to produce [Ir(OH)6]2− and then treating with HNO3 at 0 °C. UV−visible spectra show that acid condensation of [Ir(OH)6]2− results in quantitative conversion to stable, ligand-free IrOx·nH2O nanoparticles, which have an extinction coefficient of 630 ± 50 M−1cm−1 at 580 nm. In contrast, alkaline hydrolysis alone converts only 30% of the sample to IrOx·nH2O at 2 mM concentration. The acidified nanoparticles are stable for at least one month at 2 °C and can be used to make colloidal solutions between pH 1 and 13. At pH 7 and above, some hydrolysis to form [Ir(OH)6]2− occurs. Uniform IrOx·nH2O electrode films were grown anodically from pH 1 solutions, and were found to be highly active for water oxidation between pH 1 and 13.

Keywords

IridiumNanoparticleHydrolysisYield (engineering)ChemistryLigand (biochemistry)Inorganic chemistryOxideElectrochemistryMolar absorptivityColloidElectrodeNuclear chemistryMaterials scienceCatalysisPhysical chemistryNanotechnologyOrganic chemistry

Affiliated Institutions

Related Publications

Publication Info

Year
2011
Type
article
Volume
2
Issue
5
Pages
402-406
Citations
315
Access
Closed

External Links

View on DOI.org

Social Impact

Altmetric
PlumX Metrics

Social media, news, blog, policy document mentions

Citation Metrics

315
OpenAlex

Cite This

Yixin Zhao, Emil A. Hernández-Pagán, Nella M. Vargas‐Barbosa et al. (2011). A High Yield Synthesis of Ligand-Free Iridium Oxide Nanoparticles with High Electrocatalytic Activity. The Journal of Physical Chemistry Letters , 2 (5) , 402-406. https://doi.org/10.1021/jz200051c

Identifiers

DOI
10.1021/jz200051c