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

摘要

High-entropy carbide (HEC) is a promising alternative to precious metal catalystsfor the hydrogen evolution reaction (HER). However, the preparation ofnanoscale HECs is a great challenge although many methods have been developedto prepare bulk HEC materials. Herein, an electrical discharge inducedbulk-to-nanoparticle transformation method is reported, by which well dispersedsub-10 nm high entropy (MoWVNbTa)C nanoparticles with high-density surfacedefects can be directly obtained by centrifugation of the waste liquid producedduring wire-cut electrical discharge machining of bulk HEC. The resultant HECnanoparticles exhibit excellent catalytic activity and durability for HER, whichis attributed to the combination of unique microstructure generated during theextremely nonequilibrium thermodynamic process and enhanced electroniceffects induced by high configurational entropy. This facile and cost-effectivebulk-to-nanoparticle transformation method can be extended to other conductivematerials and shed light on the development of high-performance catalysts.