Three isostructural Zn/Ni nitro-containing metal-organic frameworks for supercapacitor

Abstract As a novel composite material, metal-organic frameworks have a great application in supercapacitor. In the current study, based on mixed ligands of 5-nitroisophthalic acid (H2NIPA) and 1,3-di(4-pyridyl)propane (1,3-dpp), [Zn3(NIPA)3(1,3-dpp) (H2O)2·H2O]n HU14 and two isostructural [M(NIPA) (1,3-dpp) (H2O)·2H2O] (M = Zn for HU15, M = Ni for HU16) were prepared by hydrothermal reaction. The single crystal X-ray diffraction determined that HU14 contains three different zinc ions to construct a non-porous 3D network, while the isostructure HU15 and HU16 display different center metal ions but identical porous frameworks with large brick-like channels. Due to different cations and diverse architectures, these three materials show different electrochemical properties, Ni-MOF(HU16) displays a better performance (The specific capacitance of the complexes HU14, HU15 and HU16 are 22.8 F g−1, 27.86 F g−1 and 307.4 F g−1 at 1 A g−1 and remains 60.35%,71.79% and 51% of their capacitance at a high current density of 8 A g−1, respectively.) The excellent electrochemical property may be ascribed to the intrinsic nature of Ni-MOF, unique structural feature and the particles of nanoscale size.