Fabricating solution-processable composite materials of transition metal dichalcogenides (TMDs) with ultrasmall noble metal structures employing an easy preparation method poses a significant challenge. In this study, we utilized a green, one-step synthetic method by directly employing electrochemical lithium intercalation-based exfoliated metallic TMD nanosheets (MoS₂, WS₂, and TiS₂) to reduce palladium ions (Pd²⁺) to metallic Pd⁰, leading to the deposition on their surfaces. The resulting Pd nanoparticles (Pd NPs) in composites (Pd-MoS₂, Pd-WS₂, and Pd-TiS₂) were found to be amorphous, with a size ranging from 0.81 to 1.37 nm. The impact of Pd NP size on hydrogen evolution reaction (HER) activity was elucidated. Among the fabricated composites, Pd-MoS₂ exhibits the best HER performance, attributed to its smallest Pd NP size (0.81 nm). It shows an overpotential of 70 mV at a current density of 10 mA cm⁻², along with a Tafel slope of 43 mV dec⁻¹. These HER performance metrics surpass those of most Pd-decorated 2D catalysts.

中文翻译：

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在金属过渡金属二硫属化物上制备非晶亚纳米钯纳米结构以实现高效析氢反应

采用简单的制备方法制备具有超小型贵金属结构的可溶液加工的过渡金属二硫属化物（TMD）复合材料提出了重大挑战。在这项研究中，我们采用了一种绿色的一步合成方法，直接使用基于电化学锂嵌入的剥离金属TMD纳米片（MoS ₂、WS ₂和TiS ₂）将钯离子（Pd ²⁺）还原为金属Pd ⁰，导致其表面沉积。复合材料（Pd-MoS ₂、Pd-WS ₂和Pd-TiS ₂ ）中所得的Pd纳米颗粒（Pd NPs）被发现是无定形的，尺寸范围为0.81至1.37 nm。阐明了 Pd NP 尺寸对析氢反应 (HER) 活性的影响。在所制造的复合材料中，Pd-MoS ₂表现出最好的HER性能，这归因于其最小的Pd NP尺寸（0.81 nm）。它显示在10 mA cm ^-2的电流密度下70 mV的过电势，以及43 mV dec ^-1的塔菲尔斜率。这些 HER 性能指标超过了大多数 Pd 修饰的 2D 催化剂。