Recently, the rational design of non-precious metal electrocatalysts for highly efficient hydrogen evolution reaction (HER) in alkaline media has received considerable interests in sustainable and renewable energy researches. Herein, vertically aligned and interconnected NiS₂/CoS₂/MoS₂ nanosheet array on Ni foam was prepared by a two-step procedure that conducted by the hydrothermal synthesis of Ni-Co molybdate nanosheet array as the precursor and followed by the vapor phase sulfurization to achieve in situ conversion. Basing on the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations, it can be found that the honeycomb-like structure of the Ni-Co molybdate nanosheet array was well preserved after the sulfurization process. The high-resolution TEM (HRTEM) characterization reveals that the NiS₂/CoS₂/MoS₂ nanosheet array provide abundant well-exposed active edge sites and multiple heterointerfaces towards enhanced alkaline HER performance. Electrochemical studies demonstrated that the ultrathin NiS₂/CoS₂/MoS₂ nanosheets exhibited excellent HER performance with an overpotential of 112 mV at 10 mA cm^–2 and a smaller Tafel slope of 59 mV dec^–1 in comparison with NiS₂/MoS₂ (155 mV and 89 mV dec^–1) and CoS₂/MoS₂ (124 mV and 75 mV dec^–1) sample by taking the advantage of the well-exposed multiple heterointerfaces. This work presents a facile and reliable synthetic strategy for the rational design of highly efficient electrocatalysts for the HER in alkaline solution based on non-precious metal sulfide nanocomposite.

最近，合理设计用于碱性介质中高效析氢反应 (HER) 的非贵金属电催化剂在可持续和可再生能源研究中引起了广泛关注。在此，在泡沫镍上垂直排列和相互连接的 NiS ₂ /CoS ₂ /MoS ₂纳米片阵列通过两步法制备，该两步法通过水热合成 Ni-Co 钼酸盐纳米片阵列作为前体，然后进行气相硫化就地实现转换。基于扫描电子显微镜（SEM）和透射电子显微镜（TEM）表征，可以发现Ni-Co钼酸盐纳米片阵列的蜂窝状结构在硫化过程后得到了很好的保存。高分辨率 TEM (HRTEM) 表征表明，NiS ₂ /CoS ₂ /MoS ₂纳米片阵列提供丰富的暴露良好的活性边缘位点和多个异质界面，以增强碱性 HER 性能。电化学研究表明，超薄 NiS ₂ /CoS ₂ /MoS ₂纳米片表现出优异的 HER 性能，在 10 mA cm ^{–2时的过电势为 112 mV}与 NiS ₂ /MoS ₂（155 mV 和 89 mV dec ^–1）和 CoS ₂ /MoS ₂（124 mV 和 75 mV dec ^–1）样本相比， Tafel 斜率为 59 mV dec ^–1暴露良好的多个异质界面。这项工作提出了一种简便可靠的合成策略，用于合理设计基于非贵金属硫化物纳米复合材料的碱性溶液中 HER 的高效电催化剂。