Transition metal sulfides have become some of the most promising non-precious metal catalysts due to their high specific surface area, unique electronic structure, and rich phase and property modulation methods. However, defects such as high overpotential and slow reaction kinetics hinder their implementation in electrocatalytic applications. Herein, graphene-coated sponge nickel (SNG) supported Ni₉S₈ nanowires were doped with N to adjust the electronic structure and thus improve the electrocatalytic hydrogen evolution performance of the N-Ni₉S₈@SNG core/branch electrode. The N-Ni₉S₈@SNG electrode exhibits excellent hydrogen evolution performance, with an overpotential of 98 mV at 10 mA cm⁻² and long-cycle stability with no significant attenuation of the overpotential after testing at 10 mA cm⁻² for 10 h. The results of photoelectron spectroscopy and density functional theory calculations showed that, due to the higher electronegativity of the nitrogen site, the electron density of the surrounding Ni and S atoms is changed, thereby promoting the dissociation of H₂O and the adsorption/desorption of hydrogen.

Graphic Abstract

The N-Ni₉S₈@SNG electrode exhibits excellent hydrogen evolution performance with an overpotential of 98 mV at 10 mA cm⁻² and long-cycle stability. The results of photoelectron spectroscopy and density functional theory calculations showed that, due to the higher electronegativity of the nitrogen site, the electron density of the surrounding Ni and S atoms is changed, thereby promoting the dissociation of H₂O and the adsorption/desorption of hydrogen.

中文翻译：

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氮掺杂硫化镍复合阵列电极作为析氢反应的高效电催化剂

过渡金属硫化物由于其高比表面积、独特的电子结构以及丰富的相和性质调节方法，已成为一些最有前途的非贵金属催化剂。然而，诸如高过电位和缓慢反应动力学等缺陷阻碍了它们在电催化应用中的应用。在此，石墨烯包覆海绵镍（SNG）负载的 Ni ₉ S ₈纳米线掺杂 N 以调整电子结构，从而提高 N-Ni ₉ S ₈ @SNG 核/支电极的电催化析氢性能。N-Ni ₉ S ₈@SNG 电极表现出优异的析氢性能，在 10 mA cm ^{-2 下}具有 98 mV 的过电位和长循环稳定性，在 10 mA cm ^{-2 下}测试10 小时后过电位没有显着衰减。光电子能谱和密度泛函理论计算结果表明，由于氮位点较高的电负性，改变了周围 Ni 和 S 原子的电子密度，从而促进了 H ₂ O的解离和吸附/解吸氢。

图形摘要

N-Ni ₉ S ₈ @SNG 电极表现出优异的析氢性能，在 10 mA cm ^-2时的过电位为 98 mV，并且具有长循环稳定性。光电子能谱和密度泛函理论计算结果表明，由于氮位点较高的电负性，改变了周围 Ni 和 S 原子的电子密度，从而促进了 H ₂ O的解离和吸附/解吸。氢。