Advanced Fabrication of Graphene-Integrated High-Entropy Alloy@Carbon Nanocomposites as Superior Multifunctional Electrocatalysts

Abstract

High entropy materials exhibit unparalleled reactivity and tunable electrochemical properties, putting them at the forefront of advances in electrocatalysis for water splitting. Their various interfaces and elements are purposefully engineered at the nanoscale, which is essential to enhancing their electrochemical characteristics. The exceptional catalytic efficiency observed in graphene-coated nanoparticles (NPs) with an inner high-entropy alloy (HEA) (HEA@C) is a result of the combined action of several metallic constituents. However, increasing catalytic efficiency is still a very difficult task, particularly when it comes to obtaining precise control over the composition and structure via efficient synthesis techniques. HEA@C NPs exceptional reactivity and adaptable electrochemical characteristics allow them to perform better in slow oxygen evolution (SOE) activities. The novel multilayer graphene-enhanced HEA CoNiFeCuV@C NPs electrocatalyst presented in this work is carbon-based, and transmission electron microscopy (TEM) investigations verify its efficacy. The efficiency of the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR) is greatly increased by this electrocatalyst. The electrocatalytic performance of the core–shell HEA CoNiFeCuV@C NPs is remarkable for HER, OER, and ORR, even though its highly stressed lattice has structural flaws. These catalysts reach a half-wave potential of 0.87 V in 0.1 M HClO₄ at a moderate current density of 10 mA cm^–2, with HER and OER onset potentials of 20 and 259 mV, respectively. Using cyclic voltammetry scans, the study delves deeper into the material’s evolution by examining its morphology, chemical state, and elemental makeup both before and after activation. In addition to introducing novel electrocatalysts, this study significantly enhances our understanding of the deliberate synthesis of multicomponent intermetallic high-entropy alloys.