MOF-templated synthesis of Co4S3-Co9S8 heterojunctions embedded in N-doped carbon for enhanced hydrogen evolution

In this study, a novel Co₄S₃-Co₉S₈ heterostructure embedded in N-doped carbon (Co₄S₃-Co₉S₈@NC) was successfully synthesized through thiourea-assisted sulfurization of a Co-MOF template. The obtained Co₄S₃-Co₉S₈ heterojunction material gets benefits from the synergistic effects of heteroatom-doped carbon matrix and well-defined heterostructure with many active sites. As result, the heterojunction material show enhanced hydrogen evolution reaction (HER) performance in comparison with single-component counterparts. In 1.0 M KOH, it shows enhanced HER performance of requiring only 190 mV overpotential to reach 10 mA·cm⁻², which is superior to most reported Co-based catalysts. In addition, it not only showed an almost unchanged LSV curve compared to the initial value before 2000 CV cycle, but also maintained a current density of 99.8 % during the 10 h continuous i-t test. This work provides a facile strategy for constructing high-performance Co-based heterostructured electrocatalysts for HER.