Synthesis of nickel-metal organic framework nanoplates with pyridine modulation and application to supercapacitors

Abstract

2D MOFs have been widely investigated for their improved of stability and capacitance. In this work, the two-dimensional (2D) nickel-metal organic frameworks (Ni-MOFs) were prepared by a one-pot hydrothermal reaction with the assistance of a modulator. To control the thickness and lateral dimensions at the same time, the Ni-MOF (NiBpy-Py) structure was produced through in-situ substitution by pyridine (py) in the synthesis. The prepared 2D Ni-MOF nanoplates, with a thickness of approximately 23 nm and a lateral dimension ranging from 250 nm to approximately 1 μm, have been demonstrated to be an ideal candidate for supercapacitors because of their high capacitance and well-designed chemical stability. The results of NiBpy-Py showed a high capacitance of 222.5 F g−1 at a constant current of 0.5 A g−1 in a three-electrode setup. Moreover, NiBpy-Py demonstrated a specific capacitance of 178.3 mF cm−2 in a two-electrode system. After 1000 charge-discharge cycles at a constant current of 2 A g−1, the capacitance was maintained at 128 F g−1. We believe that the synthetic method proposed in this work would contribute greatly to the further exploration of unique MOF nanostructures.