LAUSR

A highly active interface is extremely critical for the catalytic efficiency of an electrocatalyst, however, facilely tailoring its atomic packing characteristics remains challenging. Herein, we report a simple yet effective strategy to obtain copious high-energy atomic steps at the interface via controlling the solidification behavior of glass-forming metallic liquids. By adjusting the chemical composition and cooling rate, highly faceted FeNi3 nanocrystals were in-situ formed in a Fe-Ni-B metallic glass (MG) matrix, leading to the creation of order/disorder interfaces. Benefiting from the catalytically active and stable atomic steps at the jagged interfaces, the resultant free-standing FeNi3 nanocrystal/MG composite exhibits a low oxygen-evolving overpotential of 214 mV at 10 mA cm-2 , a small Tafel slope of 32.4 mV dec-1 and good stability in alkaline media, outperforming most state-of-the-art catalysts. Our approach is based on the manipulation of nucleation and crystal growth of the solid-solution nanophases (e.g., FeNi3 ) in glass-forming liquids, so that the highly stepped interface architecture can be obtained due to the kinetic frustration effect in MGs upon undercooling. We envisage that the atomic-level stepped interface engineering via the physical metallurgy method can be easily extended to other MG systems, providing a new and generic paradigm for designing efficient yet cost-effective electrocatalysts. This article is protected by copyright. All rights reserved.