Self-sacrificial template resembling a scaffold decorated with rose flowers for the development of a flexible supercapacitor electrode
摘要
Different studies have shown that metal–organic framework (MOF) materials are effective self-sacrificing templates for the fabrication of transition metal sulfides (TMSs) due to their high porosity, excellent tunability for components and structure, and abundant active sites. MOFs have been known as effective “sacrificial templates” for the synthesis and development of various TMS compounds. In this work, a self-sacrificial template strategy is used to synthesize CoMOF@CoS2 nanosheet arrays, derived from the CoMOF, which acts as a self-sacrificing template resembling rose-decorated scaffolds. These obtained nanosheet arrays not only preserve the effective structure of the CoMOF but also improve the conductivity due to the formation of cobalt sulfide. Cobalt sulfides have attracted widespread attention due to their variable redox valence states, electrical conductivity that is twice that of their metal oxide counterparts, and controllable structure and dimensions. The produced CoMOF@CoS2/CF exhibits a higher specific capacitance value of 1032.45 F g−1 in comparison with CoMOF/CF with a specific capacitance value of 368.501 F g−1 at a similar scan rate of 0.003 V s−1 in an electrolyte solution of 6.0 M KOH. The enhanced electrochemical performance is attributed to excellent fast discharge/charge performance and enhanced conductivity. The constructed asymmetric supercapacitor device indicates energy density (E) and power density (P) values of 1.47 Wh kg−1 and 4.01 kW kg−1, respectively. Also, 85.25% of the specific capacitance value is maintained after recording 2000 continuous cycles. This study demonstrates that the sacrificial template strategy is an acceptable method for fabricating flexible supercapacitor electrodes with enhanced electrochemical performance.