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.

Facile Preparation of Multiscale High‐Entropy Carbide Particles Utilizing Pulse Discharge: Phase and Microstructure Evolution

“…As an example, the sub-10 nm HETMC particles deliver high catalytic activity (a low overpotential of 160 mV at a current density of 10 mA cm À2 ) and long-term durability for the electrochemical hydrogen evolution reaction, confirming the potential application of HETMC particles in the field of energy conversion (see previous work reported in Ref. [28]).…”

“…The sintering process parameters for this ceramic block were 1820 °C maintained for 60 min with a pressure of 30 MPa, and the rest of the sintering details were the same as those reported in our previous works. [9,28] The pulse discharge processing is illustrated in Figure 10. The HETMC ceramic block was employed as the positive (þ) electrode, i.e., the workpiece electrode, and a commercial molybdenum electrode wire with a 0.18 mm diameter purchased from Jinduicheng Molybdenum Mining Guangming Co., Ltd. was used as the negative (À) electrode.…”

“…report, [28] and their intrinsic catalytic activity for the hydrogen evolution reaction was investigated. However, the formation mechanism of HETMC particles during complex pulse discharge requires further clarification.…”

Designing strategies and enhancing mechanism for multicomponent high-entropy catalysts

“…Alongside the widely used cation regulation strategy, anion regulation has been tried to prepare new type high-entropy compounds, including phosphorus-boron, 99 Page 14 of 43 Chemical Science sulfide, 100 phosphorus-sulfide 101 . Recently, as illustrated in Fig.…”

“…Besides the widely used cation regulation strategy, anion regulation has been tried to prepare new types of high-entropy compounds, including phosphorus–boron, 99 sulfide, 100 and phosphorus–sulfide. 101 Recently, as illustrated in Fig. 5h, Wang et al 99 reported a two-dimensional high-entropy metal phosphorus trichalcogenide Co 0.6 (VMnNiZn) 0.4 PS 3 , which possesses the strengths of tunable adsorption energy and a large specific surface area.…”