Electrical Discharge Induced Bulk‐to‐Nanoparticle Transformation: Nano High‐Entropy Carbide as Catalysts for Hydrogen Evolution Reaction

Abstract High‐entropy carbide (HEC) is a promising alternative to precious metal catalysts for the hydrogen evolution reaction (HER). However, the preparation of nanoscale HECs is a great challenge although many methods have been developed to prepare bulk HEC materials. Herein, an electrical discharge induced bulk‐to‐nanoparticle transformation method is reported, by which well dispersed sub‐10 nm high entropy (MoWVNbTa)C nanoparticles with high‐density surface defects can be directly obtained by centrifugation of the waste liquid produced during wire‐cut electrical discharge machining of bulk HEC. The resultant HEC nanoparticles exhibit excellent catalytic activity and durability for HER, which is attributed to the combination of unique microstructure generated during the extremely nonequilibrium thermodynamic process and enhanced electronic effects induced by high configurational entropy. This facile and cost‐effective bulk‐to‐nanoparticle transformation method can be extended to other conductive materials and shed light on the development of high‐performance catalysts.