(General Student Poster Award Winner, 2nd Place) Enhanced Oxygen Evolution Reaction Performance through Alkaline-Earth Metal Doped Fe-Rich Nano Dry-Petals: A Cost-Effective and Eco-Friendly Electrocatalyst Approach

Abstract

The progress towards hydrogen production via electrolysis technologies rely on the advancement of economical, abundant, non-toxic, stable, and efficient non-precious metal catalysts for oxygen evolution reactions (OER). As the second most abundant metal on Earth, iron (Fe) offers a cost-effective alternative to more expensive OER catalysts derived from ruthenium (Ru), iridium (Ir), cobalt (Co) and nickel (Ni). However, Fe-based catalysts typically display limited OER activity. Here we present a unique strategy of introducing an alkaline-earth metal into Fe-rich crystal for the enhanced OER activity in alkaline condition. To achieve this, a facile method was developed to obtain a nano dry-petals structured M-FeOOH electrocatalyst. The optimized M-FeOOH electrocatalyst exhibits an impressively low overpotential of +259 mV at a current density of 10 mA cm-2 in 1.0 M KOH which was found to be superior to the pristine FeOOH electrode. Through a series of experiments and density functional theory (DFT) calculations, we reveal that the addition of an alkaline-earth metal to FeOOH as a dopant optimizes the electronic structure and free energy for adsorbed intermediates synergistically. As a result, the OER activity of the M-FeOOH electrocatalyst is significantly improved. Our results highlight the possibility of doping FeOOH OER catalysts using an affordable and eco-friendly approach, setting the stage for the development of advanced OER electrocatalysts.