Synthesis of (FeCoNiCuMn)S high-entropy sulfide nanorods and its enhanced oxygen evolution reaction performance

Abstract

High-entropy sulfides (HESs) have emerged as promising electrocatalysts for the oxygen evolution reaction (OER) due to their unique compositional tunability and synergistic effects. In this work, we report the rational synthesis of (FeCoNiCuMn)S HES nanorods via a facile hydrothermal process followed by a subsequent sulfidation treatment. For comparison, (FeCoNiCu)S and (FeCoNi)S medium-entropy sulfide (MES) nanorods were also prepared under identical conditions. The morphology, crystal structure and elemental valence states of the as-prepared samples were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Benefiting from the high-entropy effect, the (FeCoNiCuMn)S HES nanorods exhibit enhanced OER performance compared to their MES counterparts. It requires an overpotential of 295 mV to achieve a current density of 10 mA/cm 2 with a small Tafel slope of 54 mV/dec, and demonstrates excellent long-term stability. The OER characterization results highlight the positive role of the multicomponent high-entropy design in boosting electrocatalytic performance. This work provides a rational strategy for developing efficient and stable HES nanorods for water oxidation.