Low Electronegativity-Induced High-Entropy Engineering for Efficient Oxygen Evolution Reaction in (NiCoFeMnCr)3S4.

Abstract

Oxygen evolution reaction (OER) electrocatalysts are typically constrained by an inherent trade-off between activity and stability. To address this, we propose a dual strategy integrating low-electronegativity induction with high-entropy engineering to develop a (NiCoFeMnCr)3S4 catalyst. The incorporation of low-electronegativity Mn and Cr optimizes the electronic structure by enhancing Bader charge transfer and upshifting the d-band center, lowering the energy barriers for oxygenated intermediates (*OH, *O, *OOH). Energy barrier analysis identifies Co and Fe as the primary active sites, with their barriers decreasing from 1.61 to 1.14 eV and from 1.73 to 1.16 eV, respectively. Concurrently, the high-entropy configuration provides thermodynamic stabilization, suppressing structural degradation. As a result, the catalyst achieves a low overpotential of 232 mV at 10 mA cm-2 in 1.0 M KOH and maintains stable operation for 70 h. Overall, the synergy of low-electronegativity induction and high-entropy effects, together with the identification of Co and Fe as the main active sites, offers a feasible strategy to mitigate the activity–stability trade-off and provides insights for designing high-entropy OER electrocatalysts.