Electronegativity-Modulated PtFeCoNiCu High-Entropy Alloy Catalysts for Efficient HER and OER

High-entropy alloy nanoparticles (HEA NPs) attract considerable attention in electrocatalysis owing to their tunable electronic structures and enhanced catalytic activity enabled by multicomponent synergy. However, the optimization of multimetal electronic structures, particularly through electronegativity differences to maximize their hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) in a single catalyst, remains technically challenging. In this work, PtFeNiCo<i>X</i> (<i>X</i>: Cu, Mo, Mn) HEA NPs with electronegativity-regulated HER and OER catalysis were synthesized via a transient high-temperature shock method (THTS), using carbonized wood (CW) as a self-supporting electrode substrate. The results demonstrate that the electronegativity differences among the mixed elements in HEA induced charge redistribution, generating high-activity Cu and Pt sites. These sites can simultaneously stabilize OH* and H* intermediates, thereby significantly improving water dissociation efficiency under alkaline conditions. At 10 mA cm^-2, PtNiCoFeCu showed excellent HER and OER overpotentials of 10 mV and 164 mV, respectively, with high stability. As both the anode and cathode material in the overall water splitting, it required only 1.48 V to reach 10 mA cm^-2. This work presents a cost-effective strategy for synthesizing high-entropy alloys as efficient electrocatalysts, demonstrating great potential for sustainable hydrogen production through water electrolysis.