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

Abstract

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 IrO_x nanoparticles supported on a gold electrode (IrO_x/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 (TOF_1.56V) of 6.2 s⁻¹, and high stability under long term catalytic turn-over, the IrO_x/Au composite provides the simplest method yet developed for highly efficient iridium oxide-based electrocatalysis of the water oxidation reaction.