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

Abstract

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.