Electroless deposition of iridium oxide nanoparticles promoted by condensation of [Ir(OH) sub(6)] super(2-) on an anodized Au surface: application to electrocatalysis of the oxygen evolution reaction

The high reactivity of anodized gold for the condensation of [Ir(OH) sub(6)] super(2-) provides a simple procedure for the electroless deposition of catalytically active IrO sub(x) nanoparticles supported on a gold electrode (IrO sub(x)/Au). With a very low overpotential ( eta ) of only about 370 mV (0.1 M NaOH) required to give a current density of 10 mA cm super(-2), an average value for a turn over frequency (TOF sub(1.56V)) of 6.2 s super(-1), and high stability under long term catalytic turn-over, the IrO sub(x)/Au composite provides the simplest method yet developed for highly efficient iridium oxide-based electrocatalysis of the water oxidation reaction.