Stretchable high-entropy alloy nanoflowers enable enhanced alkaline hydrogen evolution catalysis

High-entropy alloys have received much attention in many fields for their unique physicochemical properties, yet precise control at the atomic level in terms of size and morphology remains a great challenge. Herein, we report a kind of stretchable Pt(Co/Ni)MoPdRh HEAs nanoflowers (NFs) assembled by ultra-thin nanosheets (∼ 1.68 nm) for alkaline hydrogen evolution reaction (HER) via one-step wet chemical strategy. The mass activity of HEA NFs reaches 16.64 A mgHEA−1, which is 6.38 times higher than that of commercial Pt/C. The enhanced HER performance and stability is attributed to the multiple active sites in HEAs for reducing the water dissociation energies barriers as well as favoring H adsorption and the strain effect induced by unique structure. This work not only provides a general method for synthesizing unique structures of high entropy alloys, but also provides a fundamental understanding for the study of catalysis in HEAs.