Developing cost-effective and non-precious-metal electrocatalysts is a major challenge in water-splitting applications but is important to realize renewable energy systems. Herein, we report an electrocatalyst for the hydrogen evolution reaction (HER) composed of ultrafine cobalt-doped iron sulfide/cobalt sulfide (Co:FeS₂/CoS₂) heterostructured nanowires (NWs), which were prepared by a facile hydrothermal route. In the HER, the Co:FeS₂/CoS₂ NWs achieved a low overpotential of 69 mV at 10 mA cm^–2 and a Tafel slope of only 46 mV dec^–1. The overpotential shifted by about 3 mV over 1000 cycles along with a slight change in morphology of the Co:FeS₂/CoS₂ NWs. Density functional theory calculations and experimental results revealed that the charge transport kinetics of the FeS₂/CoS₂ heterostructure contributed substantially to the high performance of this HER electrocatalyst. These ultrafine Co:FeS₂/CoS₂ NWs represent a promising alternative to platinum-based electrocatalysts for water splitting.

中文翻译：

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超细Co：FeS ₂ / CoS ₂异质结构纳米线用于高效放氢反应

开发具有成本效益的非贵金属电催化剂是在水分解应用中的主要挑战，但对于实现可再生能源系统至关重要。在这里，我们报告了由超细掺杂钴的硫化铁/硫化钴（Co：FeS ₂ / CoS ₂）异质结构纳米线（NWs）组成的氢释放反应（HER）的电催化剂，该纳米线是通过便捷的水热法制备的。在HER中，Co：FeS ₂ / CoS ₂ NW在10 mA cm ^–2时实现了69 mV的低过电势，而Tafel斜率仅为dec ^–1时为46 mV 。过电势在1000个周期内移动了大约3 mV，并且Co：FeS ₂ / CoS的形态发生了细微变化_2个西北。密度泛函理论计算和实验结果表明，FeS ₂ / CoS ₂异质结构的电荷传输动力学极大地促进了这种HER电催化剂的高性能。这些超细的Co：FeS ₂ / CoS ₂ NW代表了用于水分解的铂基电催化剂的有前途的替代品。