In-situ formation of MOFs derivatives CoSe2/Ni3Se4 nanosheets on MXene nanosheets for hybrid supercapacitor with enhanced electrochemical performance

Abstract

Metal-organic frameworks (MOFs) have attracted extensive attention as electrode material for supercapacitor in view of their rich active sites and excellent chemical compatibility. However, the insufficient conductivity and easy agglomeration make the directly use of MOFs show impoverished electrochemical performance. Thus, constructing unique nanostructured electrode materials of MOFs or their derivatives remains a great challenge. Here, the ZIF-67-derived CoSe 2 /Ni 3 Se 4 nanosheets anchored vertically on the MXene nanosheets substrate, effectively alleviating the agglomeration of CoSe 2 /Ni 3 Se 4 nanosheets. Meanwhile, the introduction of highly conductive MXene enhances the holistic conductivity, and in turn prevents the restacking of MXene flakes. Furthermore, the close combination between CoSe 2 /Ni 3 Se 4 nanosheets and MXene nanosheets promotes faster charge transfer rate and improves the durability of the structure. Consequently, as an electrode materials for supercapacitors, the honeycomb-like MXene@CoSe 2 /Ni 3 Se 4 achieves a high specific capacitance (283 mAh g −1 at 1 A g −1 ) and an outstanding capacitance retention rate with 80% after 5000 cycles. The design strategy proposed by this work provides a novel method for developing high-performance two-dimensional nanostructured electrode materials. Honeycomb-like 2D hierarchical nanocomposite MXene@CoSe 2 /Ni 3 Se 4 nanosheets were successfully constructed by in-situ growth of MOFs on Mxene nanosheet and electrostatic interaction, which can effectively inhibit the self-polymerization of MOFs derivatives. It also improves the electrochemical performance of supercapacitors with a large specific capacitance of 1019 C g −1 at 1 A g −1 and a high cyclic stability of 80% capacity maintained over 5000 cycles. • Effectively overcomes the agglomeration problem of MOFs. • Provides a new synthesis strategy of coupling Mxene. • Constructs the honeycomb-like MXene@CoSe 2 /Ni 3 Se 4 for the first time. • The electrode materials show a high specific capacitance and an outstanding capacitance retention rate.