Aligned cobalt-based Co@CoOx nanostructures for efficient electrocatalytic water oxidation

Aligned cobalt metal nanoparticles were prepared from the pyrolysis of cobalt oxalate nanoplate precursors for efficient electro-catalytic water oxidation. The 2D morphology of the precursor guided the 2D alignment of the derived cobalt metal nanoparticles. The as-prepared Co@CoOx electrocatalyst requires an ultra-low overpotential of 289 mV to achieve a current density of 10 mA cm(-2) on a simple glassy carbon (GC) electrode in a 1 M KOH aqueous solution. The metallic nature of the bulk of the electrocatalyst and the compact alignment of the nanoparticles can facilitate the inner- and inter-particulate charge transfers.