Synthesis of high-entropy alloy nanoparticles using microwave-assisted reduction and investigation of their enhanced electrochemical hydrogen evolution activity

High-entropy alloys (HEAs) are fascinating materials for novel catalysts because of their broad compositional space, which is enabled by entropy-driven mixing. Herein, HEA nanoparticles (NPs) containing Fe, Co, Ni, Cu, and Pd were successfully synthesized on reduced graphene oxide (rGO) by microwave-assisted reduction. Compared with the corresponding monometallic catalysts, the quinary FeCoNiCuPd/rGO demonstrated greater electrocatalytic activity toward the acidic hydrogen evolution reaction. Density functional theory calculations revealed that modification of the d-band center and the hydrogen affinity induced by multielemental mixing enhanced the electrocatalytic performance of the HEA. High-entropy alloys (HEAs) are fascinating materials for novel catalysts because of their exceptional properties. In this work, HEA nanoparticles (NPs) were successfully synthesized via microwave-assisted reduction. The resultant HEA NPs showed higher catalytic activity toward the electrochemical hydrogen evolution reaction. Density functional theory calculation suggested that higher catalytic activity was induced by modification of the electronic state using quinary-elements alloying.