Spin Modulation of Antiperovskite Nitride for Industrial-Current-Density Seawater Electrolysis.

Zhong, Weigao; Li, Zhishan; Sun, Qiming; Li, Linfeng; Zhang, Xia; Wen, Longyu; Zhai, Yuling; Humayun, Muhammad et al. · ACS Nano · 2026

basic_science · Level V

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Abstract

Exploring electrocatalysts that possess both high activity and long-term durability is essential for the practical implementation of seawater electrolysis; however, achieving this goal remains a major bottleneck. Herein, a spin engineering strategy is proposed for antiperovskite nitride (CuNNi<sub>3-<i>x</i></sub>Mo<sub><i>x</i></sub>) to boost its inherent catalytic activity. The partial substitution of Ni sites with Mo atoms induces a transition from low-spin state Ni<sup>2+</sup> (e<sub>g</sub><sup>2</sup> t<sub>2g</sub><sup>6</sup>) to high-spin state Ni<sup>3+</sup>(e<sub>g</sub><sup>2</sup> t<sub>2g</sub><sup>5</sup>). The Mo-substituted catalyst exhibits superior electrocatalytic performance, yielding low overpotentials of 212 mV for the hydrogen evolution reaction (HER) and 453 mV for the oxygen evolution reaction (OER) at a current density of 500 mA cm<sup>-2</sup>. The practical viability of the spin-engineered antiperovskite catalyst is further demonstrated in an overall seawater electrolysis setup, which maintains stable operation at 500 mA cm<sup>-2</sup> for over 1000 h. The experiments and density functional theory calculations reveal that spin state modulation reduces the electron population in the σ* orbitals, thereby strengthening *OH adsorption at Ni sites. This optimizes the binding energy of *OH and promotes the transformation to the active NiOOH phase, ultimately enhancing the OER kinetics.