In-Situ Fabrication of Graphene Oxide Hybrid Ni-Based Metal–Organic Framework (Ni–MOFs@GO) with Ultrahigh Capacitance as Electrochemical Pseudocapacitor Materials

This paper reports a series of novel Ni-based metal–organic framework (Ni–MOFs) prepared by a facile solvothermal process. The synthetic conditions have great effects on the Ni–MOFs morphologies, porous textures, and their electrochemical performance. Improved capacitance performance was successfully realized by the in-situ hybrid of Ni–MOFs with graphene oxide (GO) nanosheets (Ni–MOFs@GO). The pseudocapacitance of ca. 1457.7 F/g for Ni–MOFs obtained at 180 °C with HCl as the modulator was elevated to ca. 2192.4 F/g at a current density of 1 A/g for the Ni–MOFs@GO with GO contents of 3 wt %. Additionally, the capacitance retention was also promoted from ca. 83.5% to 85.1% of its original capacitance at 10 A/g even after 3000 cycles accordingly. These outstanding electrochemical properties of Ni-based MOF materials may be related to their inherent characteristics, such as the unique flower-like architecture and fascinating synergetic effect between the Ni–MOFs and the GO nanosheets.