Anodic Electrodeposition of IrOx Nanoparticles from Aqueous Nanodroplets

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, IrO_x is a popular material for the water oxidation reaction, but electrodeposition strategies for the controlled growth of IrO_x nanoparticles are lacking. Here, we demonstrate the anodic electrodeposition of IrO_x 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. IrO_x 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 IrO_x nanoparticles under anodic conditions using water nanodroplets expands the capabilities of our technique and provides a tunable platform for IrO_x nanoparticle electrodeposition.