Hierarchical 2D/1D MOFs/electrospun ZIF-67 modified carbon nanofibers heterostructure electrode for high-performance...

In this paper, a 2 dimensional (2D) metal-organic frameworks (MOFs) nanosheets grown on 1D ZIF-67 modified carbon nanofibers (CNFs) was designed and fabricated with a hierarchical heterostructure. The hierarchical 2D/1D MOFs/CCNF offers rich electrochemical active sites and favorable ion/electron diffusion pathways. The synergistic effect of Co, CNFs and MOFs from heterostructures contributes to superb electrochemical activities. Benefiting from the hierarchical heterostructures optimized by the mass ratio of ZIF-67/PAN and CCNF/NiMOF as well as the type of substrates, CCNF-20@MOF showed a specific capacity of 361.50 C g^-1 at 0.5 A g^-1, whose charge storage mechanism is dominated by diffusion control. Meanwhile, a bamboo-derived carbon material (BBC) was designed in the solid-state asymmetric supercapacitor (CCNF-20@MOF//BBC). The device exhibited an energy density of 38.89 Wh kg^-1 at the power density of 800.02 W kg^-1 and excellent cycling stability, that exceed many MOFs based devices. Moreover, it could be successfully used for LED light-emitting, demonstrating a good application prospect. This work provides a feasible strategy for the improved performance of MOFs and CNFs based materials in the field of energy storage.