The two-dimensional (2D) transition metal dichalcogenides (TMDs) have been widely used in various electrochemical applications, such as electrocatalysts, sensors, and energy storage. They have been potentially demonstrated not only as catalysts but also as supporting materials for boosting catalytic performance and durability. However, the different types of TMD nanosheets (transition metals and chalcogenide atoms) for supporting nanoparticles have not yet been investigated for electrocatalytic performance. Herein, we provide mechanistic insights into the hydrogen evolution reaction (HER) of various TMDs (i.e., MoS₂, MoSe₂, and WSe₂) as catalyst supports for the decoration of gold nanoparticles (AuNPs), which represent an active catalyst. Among various TMD supports, it was found that the MoS₂ supports with an optimal amount of AuNPs loading (MoS₂/AuNPs) exhibited excellent catalytic activity (low overpotential and Tafel slope), which is better than that of other TMD supports and the previously reported TMD-based support. This is due to well-dispersed AuNPs with the charge transfer of Au-MoS₂ interaction (increasing n-type), leading to highly active sites for HER performance. Moreover, the perfect laminar stacking of the MoS₂/AuNPs electrode, providing high porosity and good wettability, plays an important role in enhancing the ability of ionic electrolytes to infiltrate through the electrode area (up to ∼50 F g^–1). The MoS₂/AuNPs exhibit long-term stability with no disintegration of the electrode when performing the HER at ultrahigh current density (>200 mA cm^–2) for over 24 h. This work aims to deepen the understanding of TMD materials as catalyst supports, and is advantageous for the development of catalyst-based applications.

中文翻译：

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过渡金属硫化物作为催化剂的作用 支持金纳米颗粒装饰以增强析氢反应


二维 （2D） 过渡金属硫化物 （TMD） 已广泛用于各种电化学应用，例如电催化剂、传感器和储能。它们不仅被证明是催化剂，而且还是提高催化性能和耐久性的支撑材料。然而，用于支撑纳米颗粒的不同类型的 TMD 纳米片（过渡金属和硫属化物原子）的电催化性能尚未得到研究。在本文中，我们提供了对各种 TMD（即 MoS₂、MoSe₂ 和 WSe₂）的析氢反应 （HER） 的机理见解，作为金纳米颗粒 （AuNPs） 装饰的催化剂载体，金纳米颗粒 （AuNPs），代表活性催化剂。在各种 TMD 载体中，发现具有最佳 AuNPs 负载量 （MoS₂/AuNPs） 的 MoS₂ 载体表现出优异的催化活性（低过电位和塔菲尔斜率），这优于其他 TMD 载体和先前报道的基于 TMD 的载体。这是由于分散良好的 AuNPs 与 Au-MoS₂ 相互作用的电荷转移（增加 n 型），导致 HER 性能的高活性位点。此外，MoS₂/AuNPs 电极的完美层状堆叠提供了高孔隙率和良好的润湿性，在增强离子电解质渗透电极区域的能力（高达 ∼50 F g^–1）方面发挥着重要作用。MoS₂/AuNPs 在超高电流密度 （>200 mA cm^–2） 下进行 HER 超过 24 小时时表现出长期稳定性，电极不会崩解。 这项工作旨在加深对 TMD 材料作为催化剂载体的理解，有利于基于催化剂的应用开发。