Transition metal dichalcogenides (TMDs) are an intriguing family of materials with large application potential in a variety of scientific fields ranging from electronics to electrocatalysis. Within this group of materials, MoS₂ has been attracting a lot of scientific attention due to its chemical and physical properties. In this report, we studied the exfoliation of the largely unexplored 3R MoS₂ polytype prepared by high-temperature, high-pressure synthesis. Bulk as well as sodium naphthalenide exfoliated materials were studied in terms of their quality and performance for the hydrogen evolution reaction (HER). The HER performance was benchmarked versus the commonly available 2H polytype. The reported results show that the 3R polytype is more suitable for the conversion of MoS₂ into the metallic 1T phase, which was attributed to surface oxidation occurring in the 2H polytype. Higher content of the 1T phase then resulted in an overall lower overpotential of −0.25 V vs. RHE for the 3R polytype compared with the overpotential of −0.30 V for the 2H polytype. These results show that the 3R polytype might serve as a better starting point for the synthesis of highly active chemically exfoliated MoS₂ catalysts for hydrogen evolution.

中文翻译：

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MoS2 堆积很重要：3R 多型体在析氢反应方面明显优于 2H MoS2

过渡金属二硫属化物 (TMD) 是一个有趣的材料家族，在从电子到电催化的各种科学领域中具有巨大的应用潜力。在这组材料中，MoS ₂由于其化学和物理特性而引起了很多科学界的关注。在本报告中，我们研究了通过高温高压合成制备的大部分未开发的 3R MoS ₂多型体的剥离。研究了散装和萘化钠剥离材料的质量和析氢反应 (HER) 性能。在她的成绩是基准对比常见的 2H 多型。报道的结果表明，3R 多型更适合将 MoS ₂转化为金属 1T 相，这归因于 2H 多型中发生的表面氧化。1T 相的含量越高，整体过电位越低 -0.25 V与. 3R 多型的 RHE 与 2H 多型的 -0.30 V 过电位相比。这些结果表明，3R 多型体可能是合成用于析氢的高活性化学剥离 MoS ₂催化剂的更好起点。