Facile preparation of porous high-entropy alloy FeCoNiCuMn and its OER performance

A high-entropy metal-organic framework (MOF) is synthesized as a precursor by using a one-step solvothermal method, which is converted into a face-centered cubic high-entropy alloy (FeCoNiCuMnZn) after the thermal reduction in an Ar/H2 atmosphere. Due to its low boiling point, metallic Zn, as a sacrificial template, is evaporated from the alloy during the thermal reduction process and leaves room or pore, and thus porous high-entropy alloy nanoparticles (FeCoNiCuMn-NPs) form. The porous high-entropy alloy nanoparticles have the largest electrochemically active surface area (3810 cm2), and exhibit excellent OER performance: At a current density of 10 mA cm−2, the overpotential is 196 mV, and the Tafel slope 55 mV dec−1. In addition, the porous high-entropy alloys nanoparticles-based electrode remain stable even after 75 h of continuous operation.