Bifunctional and Efficient CoS2–C@MoS2 Core–Shell Nanofiber Electrocatalyst for Water Splitting

It is highly desirable to develop alternative non-noble metal hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalysts with the advantages of low cost and high efficiency. In this study, we report the synthesis of CoS2–C@MoS2 core–shell nanofibers by using electrospun Co–carbon nanofibers as templates, followed by a one-step hydrothermal reaction accompanied with a sulfurization process. Benefiting from the unique structure and the synergistic effect between the components, the resultant CoS2–C@MoS2 core–shell nanofibers exhibit excellent electrocatalytic activity and stability toward HER, showing the overpotential of approximately 173 mV at 10 mA cm–2 and virtually immobile current density after 1000 cycles. Furthermore, the CoS2–C@MoS2 core–shell nanofibers also show a good OER catalytic activity, providing them as efficient candidates for bifunctional water splitting electrocatalysts.