Influence of Er2O3 Nanoclusters on Transition Metal Oxide Nanostructures in Water Oxidation

The search for an effective, stable, and economically viable electrocatalyst for water splitting to replace expensive noble catalysts remains imperative. This investigation evaluates the impact of erbium oxide (Er2O3) on the oxygen evolution reaction (OER) activity of transition metal oxides (TMOs), including nickel oxide (NiO), cobalt oxide (Co3O4), and iron oxide (Fe2O3). Introducing Er2O3 nanoclusters into TMO nanostructures produces a heterostructure interface between Er2O3 and the active TMOs, leveraging Er2O3's unique 4f electron occupancy as an effective electronic modulator, thus enhancing its electrocatalytic activity. Findings reveal that the Er2O3 and Fe2O3 hybrid (ErFeO) exhibits the most promising OER activity, characterized by low overpotential and Tafel slope, exceptional durability relative to synthesized materials, and outperforming the commercial noble catalyst, RuO2. Consequently, ErFeO is a prospective electrocatalyst for OER applications.