Eutectic-derived high-entropy nanoporous nanowires for efficient and stable water-to-hydrogen conversion

Combining multiple metal elements into one nanostructure merits untold application potential but is still a challenge for the traditional bottom-up synthesis method. Herein, we propose a eutectic-directed self-templating strategy to prepare two multi-component nanostructured alloys (PtPdRhIrNi (D-SN) and NiPtPdRhIrAl (D-SS)) through the combination of rapid solidification with dealloying. The PtPdRhIrNi nanoporous nanowires (NPNWs) represent a new family of high-entropy alloys (HEAs) containing delicate hierarchical nanostructure with ultrafine ligament sizes of ~ 2 nm in addition to one-dimensional (1D) morphology. Moreover, the PtPdRhIrNi NPNWs display excellent electrocatalytic activity and stability toward hydrogen evolution reaction, with the low overpotential of 22 and 55 mV to afford a current density of 10 mA·cm⁻² in 0.5 M H₂SO₄ and 1.0 M KOH electrolytes, respectively. The enhanced electrocatalytic performance can be attributed to the high-entropy effect favoring the surface electronic structure for the optimized activity, the promotion impact of Ni, 1D morphology facilitating the electron transport, and the nanoporous structure promoting the electrolyte diffusion.