01981nas a2200181 4500008004100000022001400041245013300055210006900188260000800257300001600265490000700281520129500288100001901583700001801602700002801620700002401648856012701672 2025 eng d a1144-054600aFabrication of a 3D iron-modified NiCo2S4 structure on nickel foam as a bifunctional electrocatalyst for overall water splitting0 aFabrication of a 3D ironmodified NiCo2S4 structure on nickel foa cJUN a10056-100640 v493 a

The development of highly efficient bifunctional electrocatalysts that operate effectively in strong electrolytes, with low overpotentials at defined current densities and excellent durability, has become a central focus in research on overall water splitting. In this study, a three-dimensional (3D) sheet-wrapped wire electrocatalyst, composed of Fe-doped NiCo2S4 on nickel foam (NF), was fabricated. This material demonstrated excellent durability for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in an alkaline medium. The uniform distribution of Ni, Co, Fe, and S elements significantly enhanced the electro-catalytic performance. The incorporation of Fe improved activity, with the Fe2.5%-NiCo2S4/NF electrocatalyst achieving overpotentials of 310 mV and 260 mV for the HER and OER, respectively, at a current density of 100 mA cm-2. These results were superior to those of both bare nickel foam and NiCo2S4/NF. The 3D configuration facilitated efficient ion transport and contributed to the remarkable catalytic performance. As a water-splitting electrolyzer in an alkaline electrolyte of 1.0 M KOH, the system delivered a current density of 20 mA cm-2 at a cell voltage of 1.66 V, highlighting the effectiveness of this design strategy.

1 aSingla, Gourav1 aMahajan, Mani1 aBhange, Siddheshwar, N.1 aKashyap, Varchaswal uhttps://library.ncl.res.in/content/fabrication-3d-iron-modified-nico2s4-structure-nickel-foam-bifunctional-electrocatalyst