Anodic Electrodeposition of IrOx Nanoparticles from Aqueous Nanodroplets

Abstract

Electrodeposition has been used for centuries to create new materials. However, synthetic platforms are still necessary to enrich a variety of nanomaterials that can be electrodeposited. For instance, IrOx is a popular material for the water oxidation reaction, but electrodeposition strategies for the controlled growth of IrOx nanoparticles are lacking. Here, we demonstrate the anodic electrodeposition of IrOx nanoparticles from aqueous nanodroplets. Field emission scanning electron microscopy (FESEM) and scanning transmission electron microscopy (STEM) images confirm the macro- and microstructure of the resulting nanoparticles. IrOx nanoparticles of 43 ± 10 nm in diameter were achieved. X-ray photoelectron spectroscopy (XPS) showed the presence of Ir(III) and Ir(IV) hydrated oxyhydroxide species. The synthesis of IrOx nanoparticles under anodic conditions using water nanodroplets expands the capabilities of our technique and provides a tunable platform for IrOx nanoparticle electrodeposition.