High-entropy-alloy nanoparticles synthesized by laser metallurgy using a multivariate MOF

Abstract

We report the synthesis of multivariate MOFs with combinations of metal ions, including Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺. The permanent porosity and the evenly distributed metal components make these porous crystals ideally suited for the synthesis of alloy nanoparticles. Using a laser, these MOFs are converted in air to alloy nanoparticles of binary (FeNi, FeCo), ternary (FeCoNi) and high-entropy-alloys with quinary (MnFeCoNiCu, MnFeCoNiZn) metals. One member, FeNi alloy nanoparticles with a narrow particle size distribution around 7 nm, shows a low overpotential of 282 mV at a current density of 10 mA cm⁻² in the oxygen evolution reaction (OER), better than those of the single metal counterparts. This demonstrates the possibility of using MOFs to produce alloy nanoparticles with multiple metal components by a laser.