Nanosheets of Co-(Ni and Fe) Layered Double Hydroxides for Electrocatalytic Water Oxidation Reaction

Abstract

The discovery of new nanomaterials as catalysts to produce hydrogen through artificial photosynthesis approach has become essential in the development of sustainable energy infrastructures. Large hydrogen demands could be tackled by splitting water into storable hydrogen and oxygen. Here, we report a novel nanomaterial that consists of a layered double hydroxide (LDH) based on Co-Fe and well-dispersed Co-Fe hydroxide nanoparticles (NPs) that is capable to perform the water oxidation reaction (WOR) effectively. Also, we compared the electrocatalytic behavior of this layered material against a Co–Ni LDH in WOR. Cyclic Voltammetry (CV) results show that the Co–Fe LDH catalyst exhibits lower overpotential (i.e., ~200 mV less, in aqueous 0.1 M phosphate buffer at neutral pH) than Co–Ni LDH. We attribute this behavior to a synergistic effect between the Co–Fe hydroxide NPs and Co–Fe LDH; different morphology of the Co-Fe hydroxide in contact could lead to a change in the electronic structure of the surface.