Fabrication of graphite nanosheets decorated with Ni-MOFs for high performance supercapacitor electrode materials

Metal-organic frameworks (MOFs) with a periodic network structure are formed by self-assembled coordination links between one or more metal centers and organic ligands. In recent years, MOFs as electrode materials for supercapacitors (SCs) have been favored by researchers due to the tunable pore sizes, high surface area, and abundant active sites. However, the disadvantages of MOFs such as poor electrical conductivity and electro-chemical stability limit their further application. In this work, nickel MOFs (Ni-MOFs) were grown in situ on graphite nanosheets (GNS) to form GNS decorated with Ni-MOFs (Ni-MOFs/GNS) by one-pot solvothermal method. The electrochemical properties of the Ni-MOFs/GNS as electrode materials could be tuned by adjusting the amount of GNS and the experimental conditions to regulate the structures. Moreover, Ni-MOFs grown in situ in GNS could improve the conductivity and dispersion of Ni-MOFs to avoid aggregation. The results indicated that the specific capacity of the Ni-MOFs/GNS electrode materials obtained at the optimal experimental con-ditions was 737.0C g-1 at 1 A g-1, and the capacity retention rate reached 61.1 % after 10,000 cycles. The power density was 424.0 W kg- 1 at an energy density of 30.0 Wh kg -1. The fabrication strategy of the Ni-MOFs/GNS can be extended to synthesize other functional materials.

Automated summary

In this study, nickel metal-organic frameworks (Ni-MOFs) were grown in situ on graphite nanosheets (GNS) to form GNS decorated with Ni-MOFs (Ni-MOFs/GNS) using a one-pot solvothermal method. The electrochemical properties of the Ni-MOFs/GNS as electrode materials could be tuned by adjusting the amount of GNS and the experimental conditions to regulate the structures. Moreover, the in situ growth of Ni-MOFs in GNS improved the conductivity and dispersion of Ni-MOFs to avoid aggregation. The specific capacity of the Ni-MOFs/GNS electrode materials obtained at the optimal experimental conditions was 737.0C g-1 at 1 A g-1, and the capacity retention rate reached 61.1% after 10,000 cycles. The power density was 424.0 W kg-1 at an energy density of 30.0 Wh kg-1.