Hydrogen holds great promise in the pursuit of decarbonizing energy systems. One of the key processes in hydrogen production is the hydrogen evolution reaction (HER), which relies on efficient catalysts. Cobalt sulfide (CoS) has attracted significant attention owing to its exceptional catalytic activity for HER. However, it suffers from low intrinsic catalytic activity. In this study, we aimed to enhance the catalytic activity of CoS materials for HER by fabricating cobalt sulfide on Ni foam (NF@CoS) through hydrothermal synthesis and applying surface modification techniques such as plasma treatment. Various gases, including H₂, O₂, N₂, and Ar, were used to subject CoS to plasma treatment. The results demonstrated that the optimal sample, named AP-NF@CoS, obtained through Ar plasma treatment, exhibited the lowest overpotential of 133 mV at a current density of 50 mA cm^–2. Furthermore, the AP-NF@CoS sample displayed excellent performance, with a Tafel slope of 129 mV dec^–1. These findings indicate that plasma treatment on NF@CoS is an effective method for producing high-performance electrocatalysts for the HER.

中文翻译：

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等离子体处理硫化钴纳米粒子/泡沫镍电催化剂的析氢反应

氢在追求能源系统脱碳方面有着巨大的前景。氢气生产的关键过程之一是析氢反应（HER），它依赖于高效的催化剂。硫化钴（CoS）由于其优异的析氢反应催化活性而引起了广泛关注。然而，它的固有催化活性较低。在这项研究中，我们旨在通过水热合成在泡沫镍上制备硫化钴（NF@CoS）并应用等离子体处理等表面改性技术来增强CoS材料的HER催化活性。使用各种气体，包括H ₂、O ₂、N ₂和Ar，对CoS进行等离子体处理。结果表明，通过Ar等离子体处理获得的最佳样品AP-NF@CoS在50 mA cm ^–2的电流密度下表现出133 mV的最低过电势。此外，AP-NF@CoS 样品表现出优异的性能，塔菲尔斜率为 129 mV dec ^–1。这些发现表明，对 NF@CoS 进行等离子体处理是生产高性能 HER 电催化剂的有效方法。