Rapid synthesis of subnanoscale high-entropy alloys with ultrahigh durability

Subnanoscale (<2 nm) high-entropy alloys (SHEAs) have garnered increasing attention for their unique physicochemical properties that enable high catalytic performance. However, this potential is offset by reduced stability, a characteristic typically associated with high-entropy alloys, due to their high reactivity at this scale. Here we circumvent this obstacle by using the localized surface plasmon resonance effect along with laser fragmentation in liquids for synthesizing SHEAs. Localized-surface-plasmon-resonance-generated hot electrons from gold nanoparticles facilitate metal ion reduction, whereas the 7-ns laser pulse induces ultrafast heating and cooling cycles, fusing multiple metals into SHEAs with enhanced stability. This method enables the incorporation of up to ten elements into SHEAs. The selected AuPtRuRhIr SHEAs demonstrate high stability to work under 2 A cm^-2 at 2.12 V for over 1,200 h in a proton exchange membrane electrolyser. This work presents a general strategy for the preparation of SHEAs, applicable across a wide range of fields.