Transition metal dichalcogenides (TMDs) hold a great promise to replace Pt-based catalysts for hydrogen evolution reaction (HER). Among those, MoS 2 has been the center of attention. In this work, we investigate the effect of Ni addition on the catalytic activity of MoS 2 thin film in HER. Ni–Mo–S ternary chalcogenide thin films with varying Ni concentrations were fabricated by a two-step process: co-sputtering of Ni-Mo alloy films and thermal sulfurization. The HER performance of MoS 2 (620 mV overpotential and 138 mV dec −1 Tafel slope) is surpassed by the resulting ternary chalcogenides, among which the Ni–Mo–S film at 50 at.% Ni concentration exhibits the highest catalytic activity with an overpotential of 400 mV at 10 mA cm −2 and Tafel slope of 81 mV dec −1 . The Ni addition promotes HER kinetics by altering the morphology and electronic structure of MoS 2 thin film, leading to improved H + ion adsorption, reduced charge transfer resistance and increased electrochemical surface area. This study provides a method for the controllable fabrication of ternary chalcogenide thin films and paves the way for the exploration of new combinations of ternary TMDs. Graphic Abstract

中文翻译：

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用于增强析氢反应的 Ni-Mo-S 三元硫属化物薄膜

过渡金属二硫属化物 (TMD) 有望取代 Pt 基催化剂用于析氢反应 (HER)。其中，MoS 2 一直是关注的焦点。在这项工作中，我们研究了 Ni 添加对 HER 中 MoS 2 薄膜催化活性的影响。具有不同 Ni 浓度的 Ni-Mo-S 三元硫族化物薄膜通过两步工艺制备：Ni-Mo 合金薄膜的共溅射和热硫化。MoS 2 的 HER 性能（620 mV 过电位和 138 mV dec -1 Tafel 斜率）被所得的三元硫属化物超越，其中 Ni-Mo-S 膜在 50 at.% Ni 浓度下表现出最高的催化活性， 10 mA cm -2 时的过电位为 400 mV，Tafel 斜率为 81 mV dec -1 。Ni的添加通过改变MoS 2 薄膜的形态和电子结构来促进HER动力学，从而改善H + 离子吸附、降低电荷转移电阻和增加电化学表面积。该研究为三元硫属化物薄膜的可控制备提供了一种方法，并为探索三元TMDs的新组合铺平了道路。图形摘要