Large-scale multirole Zn(Ⅱ) programmed synthesis of ultrathin hierarchically porous carbon nanosheets

作者:XU LingSong; MENG FanCheng; WEI XiangFeng; LIN ChangHao; ZHENG LianXi*; LIU JieHua*
来源:Science China Technological Sciences, 2020, 63(09): 1730-1738.

摘要

ZIF-derived carbon structures are considered as desired electrode materials for supercapacitors due to their high surface area,high conductivity, and porous structure. However, the most reported ratio of 2-methylimidazole and Zn(II) is 4:1 to 20:1, which limits commercial applications due to the increasing cost. In this paper, a multirole Zn(II)-assisted method is presented from Zn(II) solution, Zn O, Zn O/ZIF-8 core-shell nanostructure, to 3 D hierarchical micro-meso-macroporous carbon structures with a1:1 ratio of 2-methylimidazole and Zn(II). The hierarchically porous carbon has a high surface area of 1800 m2 g-1 due to the synergistic effect of multirole Zn(II). The unique carbon-based half-cell delivers the specific capacitances of 377 and 221 F g-1 at the current densities of 1.0 and 50 A g-1, respectively. As a 2.5 V symmetrical supercapacitor, the device reveals a high doublelayer capacitance of 24.4 F g-1, a power density of 62.5 k W kg-1, and more than 85.8% capacitance can be retained over 10000 cycles at 10 A g-1. More importantly, the low-cost hierarchically porous carbon could be easily produced on a large scale and almost all chemicals can be reused in the sustainable method.