Metal Organic Framework Derived Core-Shell Structured Co₉S₈@N-C@MoS₂ Nanocubes for Supercapacitor

Transition metal sulfides with designed nanostructure have attracted significant research interest as electrode materials for supercapacitors. In this work, core-shell structured Co₉S₈@N-C@MoS₂ nanocubes have been successfully fabricated through a sulfuration process based on ZIF-67 precursor. Due to improved electrical conductivity and large surface area, Co₉S₈@N-C@MoS₂ nanocubes with core-shell heterostructure exhibit better electrochemical performance in supercapacitors compared with Co₉S₈. Moreover, the morphology of core-shell structured Co₉S₈@N-C@MoS₂ nanocubes can be well-adjusted by tuning the ratio between Co₉S₈ and MoS₂. The homogeneous core-shell structured Co₉S₈@N-C@MoS₂ nanocubes (S-3) can be obtained with the mass ratio of Na₂MoO₄·2H₂O and CH₄N₂S at 1:2. And the obtained core-shell structured S-3 delivers a high specific capacitance of 410.0 F g^-1 at the current density of 10.0 A g^-1 after 20000 cycles with excellent cycling stability (101.7% of the initial value). The excellent electrochemical property is mainly due to the unique structure which induces synergistic effects between Co₉S₈ and MoS₂.