Impact of various reaction conditions of solvothermal synthesis on electrochemical properties of Ni-MOF materials

Abstract A series of Ni-MOF materials were synthesized by a one-step solvothermal method under different reaction conditions, including metal source, organic ligand, reaction time and reaction temperature. The results demonstrated that the Ni-MOFs synthesized with Ni(NO3)2•6H2O as the metal source had higher crystallinity and a more uniform crystalline structure than those with NiCl2•6H2O. Different organic ligands led to the formation of Ni-MOFs in various morphologies. With the increase of reaction time, the crystal particles gradually became smaller, and the hexagonal lamellar block gradually transformed into spherical block crystals. Besides, the capacity retention of the material varied with different reaction temperatures. The highest specific capacitance reached 1996 F•g-1 at a current density of 1 A•g-1 when the temperature was 140 ℃. After 3,000 cycles at 10 mA, the material demonstrated a capacity retention of 1 A•g-1 with a capacity retention rate of 74.82%. The synthesis method and material structure of Ni-MOFs could be improved to facilitate their widespread application in the field of supercapacitors, thereby accelerating the advancement of energy storage technology.