Manipulating the Electrochemical Surface Reconstruction of Nickel Foam via Electrolyte Engineering for Efficient Oxygen Evolution Reaction at Industrial-Level Current Density

The surface reconstruction process happened to electrocatalysts for creating active sites, which has been evidenced to determine the electrocatalytic activity for water splitting. Herein, the electrolyte conditions (i.e., OH^- and Fe³⁺) were engineered to manipulate the surface reconstruction process happened to nickel foam (NF) for forming Fe-incorporated γ-NiOOH phases, and a low overpotential of only 267 mV could be achieved for alkaline oxygen evolution reaction (OER) at the current density of 100 mA cm^-2. More excitingly, the anion exchange membrane water electrolyzer (AEMWE) with Fe-incorporated γ-NiOOH phases created on NF as the anode could survive from a 100-h operation at an industrial-level current density of 1 A cm^-2. The OH^- ions in the electrolyte could promote the dissolution-redeposition process with created γ-NiOOH phases active for the OER, and meanwhile boost the incorporation of Fe into the formed γ-NiOOH phases, thermodynamically facilitating the formation of O* intermediates for improved OER performance.