氮掺杂多孔MOF衍生碳电极的构筑及其电化学性能

Fabrication and electrochemical properties of nitrogen doped MOF-derived carbon electrodes

通过两步法成功将氮掺杂石墨烯量子点(N-doped graphene quantum dots,N-GQDs)与金属有机骨架衍生碳材料(cZIF-8)组合制备出N-GQDs@cZIF-8超级电容器.1 mol/L H2SO4电解质中,该电极在0.5 A·g^−1电流密度下具有246.6 F·g^−1的比容量,在循环8000次时仍然保持83.7%的容量保留率,展现了优异的循环稳定性.同时,NGQDs@cZIF-8超级电容器在104.5 W·kg^−1的功率密度下获得了8.2 W·h·kg^−1的优异能量存储能力,这样显著的电化学性能主要因其具有高比表面积的三维结构和高赝电容活性的氮掺杂水平(10.13%),使其在超级电容器、锂离子电池等能量存储领域具有潜在的应用前景.

The N-GQDs@cZIF-8 supercapacitor has been fabricated following a two-step process through combining N-doped graphene quantum dots(N-GQDs)with metal-organic framework-derived carbon material(cZIF-8).The N-GQDs@cZIF-8 electrode has a high specific capacitance of 246.6 F·g^−1 at a current density of 0.5 A·g^−1 in 1 mol/L H2SO4 electrolyte and has excellent cycle stability with 83.7%capacity retention over 8000 cycles.At the same time,the N-GQDs@cZIF-8 supercapacitor achieves an excellent energy density of about 8.2 W·h·kg^−1 at a power density of 104.5 W·kg^−1.The outstanding electrochemical performance of the device owes much to its 3D structure with high specific surface area and high nitrogen doping level(10.13%)with high pseudo capacitive activity,which makes this electrode have potential application in the field of supercapacitors and lithium-ion batteries.