Metal-organic framework derived hierarchical zinc nickel selenide/nickel hydroxide microflower supported on nickel foam with enhanced electrochemical properties for supercapacitor

摘要

As a kind of electrode materials, zeolite imidazole frameworks have attracted extensive interest for supercapacitor in virtue of its high porosity, large specific surface area and structural diversity. Herein, a novel composite Zn-Ni-Se/Ni(OH)_2 hierarchical microflower composed of looser and corrugated nanosh-eets has been successfully fabricated with coprecipitation and an uncomplicated two-step hydrothermal method utilizing zeolite imidazole frameworks-8 as precursor. The resultant Zn-Ni-Se/Ni(OH)_2-based electrode exhibits markedly improved electrochemical properties with a specific capacitance of 1632.8 F g~(-1) at 2 A g~(-1) and superior cycling stability (85.4% of the initial retention after 2000 cycles at 6 A g~(-1), which are superior to those of Zn-Ni-Se and Ni(OH)_2 electrodes. The enhanced performance of Zn-Ni-Se/Ni(OH)_2 composite is attributed to the synergistic contributions from Zn-Ni-Se and Ni(OH)_2 materials together with the superior properties of specific hierarchical microflower structure. This work provides a meaningful guidance for designing and preparing other composites with distinctive morphologies for pseudocapacitor application.