MOF-derived self-sacrificing route to hollow NiS2/ZnS nanospheres for high performance supercapacitors

摘要

Transition metal sulfides have complex valence states and exhibit excellent properties and promising applications in supercapacitors. NiS2/ZnS hollow spherical nanocomposites have been successfully synthesized via a facile MOF-derived self-sacrificing route. The synthesis process involves solvothermal method for preparation of Ni/Zn-BDC MOF and subsequently chemical sulfidation treatment to convert into NiS2/ZnS hollow nanospheres. When evaluated as electrode materials in supercapacitor, the NiS2/ZnS hollow nanospheres exhibit high capacitance of 1198 F g(-1) at the current density of 1 A g(-1). Moreover, an asymmetric supercapacitor based on NiS2/ZnS hollow nanospheres as the positive electrode and activated carbon (AC) as the negative electrode achieves an energy density of 28.0 W h kg(-1) at a power density of 478.9 kW kg(-1). The results suggest the NiS2/ZnS hollow nanospheres are promising electrode materials for high-performance supercapacitors.