Abstract The development of earth-abundant electrocatalysts to replace high-cost precious metal Pt for water splitting to generate H2 is a hot topic in the researches on clean energy. Among them, MoS2 nanostructures have intrigued great interest for its low cost and potential high performance. However, due to the intrinsically low conductivity, its H2 evolution activity is not satisfactory as an applicable electrocatalyst. Herein we report a novel MoS2/FeS2 nanocomposite grown directly on carbon cloth by a facile method based on simple one-step chemical vapor deposition, which has significantly improved H2 evolution performance compared to its pure MoS2 nanosheets counterpart. Such self-supported MoS2/FeS2 nanocomposite electrode exhibits a relatively low overpotential of 134 mV at a current of 10 mA cm−2, a quite small Tafel slope of 76.8 mV⋅dec−1 and excellent electrocatalytic durability in 0.5 mol L−1 H2SO4. The remarkably high H2 evolution activity could be ascribed to the fully exposed and increased number of active sites, enhanced charge transfer rate between MoS2 nanosheets and FeS2 nanoparticles in the composite, and the 3D self-supported structure. This strategy to prepare MoS2/FeS2 nanocomposite with controllable morphology and highly active microstructure would provide a new way for the improvement of the electrocatalytic H2 evolution activity and durability of MoS2.

中文翻译：

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新型自支撑 MoS2/FeS2 纳米复合材料作为优异的析氢电催化剂

摘要 开发地球储量丰富的电催化剂以替代高成本的贵金属Pt进行水分解制氢是清洁能源研究的热点。其中，MoS2 纳米结构因其低成本和潜在的高性能而引起了极大的兴趣。然而，由于其固有的低电导率，其析氢活性作为一种适用的电催化剂并不令人满意。在此，我们报告了一种通过基于简单一步化学气相沉积的简便方法直接在碳布上生长的新型 MoS2/FeS2 纳米复合材料，与纯 MoS2 纳米片相比，该复合材料显着提高了析氢性能。这种自支撑的 MoS2/FeS2 纳米复合电极在 10 mA cm−2 的电流下表现出相对较低的 134 mV 过电位，非常小的 Tafel 斜率 76。在 0.5 mol L-1 H2SO4 中具有 8 mV⋅dec-1 和出色的电催化耐久性。显着高的 H2 析出活性可归因于完全暴露和增加的活性位点数量、复合材料中 MoS2 纳米片和 FeS2 纳米颗粒之间的电荷转移率提高以及 3D 自支撑结构。这种制备具有可控形貌和高活性微观结构的 MoS2/FeS2 纳米复合材料的策略将为提高 MoS2 的电催化析氢活性和耐久性提供新的途径。和 3D 自支撑结构。这种制备具有可控形貌和高活性微观结构的 MoS2/FeS2 纳米复合材料的策略将为提高 MoS2 的电催化析氢活性和耐久性提供新的途径。和 3D 自支撑结构。这种制备具有可控形貌和高活性微观结构的 MoS2/FeS2 纳米复合材料的策略将为提高 MoS2 的电催化析氢活性和耐久性提供新的途径。