Electroless deposition of iridium oxide nanoparticles promoted by condensation of [Ir(OH)6]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)6]2− provides a simple procedure for the electroless deposition of catalytically active IrOx nanoparticles supported on a gold electrode (IrOx/Au). With a very low overpotential (η) of only about 370 mV (0.1 M NaOH) required to give a current density of 10 mA cm−2, an average value for a turn over frequency (TOF1.56V) of 6.2 s−1, and high stability under long term catalytic turn-over, the IrOx/Au composite provides the simplest method yet developed for highly efficient iridium oxide-based electrocatalysis of the water oxidation reaction.