Abstract
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Highly efficient electrocatalysts for the oxygen evolution reaction (OER) are very important for various energy storage and conversion systems such as water splitting devices and metal-air batteries. However, developing OER electrocatalysts with high activity and excellent stability at a high current density remains a considerable challenge. Herein, a facile room-temperature-stirring strategy is described to obtain FeCoNi layered double hydroxide nanocages (FeCoNi-LDHs) using a metal���organic framework as a precursor. The FeCoNi-LDHs have hollow features, while their walls are assembled with ultrathin layered hydroxide nanosheets. By designing a unique structure and tuning the composition, high activity and robust long-term stability of the FeCoNi-LDHs for the OER outperform IrO2, used as the reference catalyst. The as-obtained high electrochemically active surface area and the decreased transfer resistance are ascribed to the significantly improved activity. Density functional theory calculations suggest that the introduction of Fe can fine-tune the electronic structure and decrease the Gibbs free energy difference of the rate-determining step (��G3), improving the intrinsic activity of FeCoNi-LDHs toward the OER. Furthermore, the proposed room-temperature-stirring strategy can be easily scaled up to more than 10 grams of nanocages through a single batch reaction process, demonstrating the large-scale applicability of the catalysts.