High-entropy borides with frame structure: Efficient electrocatalysts for oxygen evolution reaction

Innovative methods for producing catalytic nanomaterials are crucial for advancing environmental conversion and storage technologies. This study introduces a novel approach to fabricate a high-entropy boride alloy with a frame structure, FeCoNiMgB/NF, using in situ growth of high-entropy alloy powder on nickel foam (NF). The resulting frame-structured FeCoNiMgB/NF high-entropy boride alloy exhibits superior electrocatalytic performance for the oxygen evolution reaction (OER) compared to pure FeCoNiMgB powder and other counterparts. It demonstrates a low overpotential of 183 mV at a current density of 10 mA cm−2, a Tafel slope of 34 mV dec−1 in 1 M KOH, and excellent stability over 72 h without significant decay. The outstanding catalytic performance of the frame-structured FeCoNiMgB/NF high-entropy alloy can be attributed to the synergistic effects of FeCoNiMgB–NF, a larger specific surface area, and excellent frame-structure conductivity. The alloy's long-term stability is a result of the gradual formation of the FeCoNiMgOOH lath structure array during the reaction process, facilitating low adsorption and charge transfer energies as per theoretical calculations. This study presents a new method for constructing advanced frame-structured high-entropy boride alloys, promising advancements in energy conversion and storage technologies.