Trimesic acid-modified 2D NiCo-MOF for high-capacity supercapacitors

In this article, a trimesic acid-mediating control synthesis strategy was proposed for preparing the NiCo-MOF composition structure of microsphere and nanosheet by substituting 1,4-dicarboxybenzene with trimesic acid. Then the pre-synthesized MOF, as a precursor and template, was further vulcanized by a facile hydrothermal method to obtain hollow microsphere and nanosheet interleaved nickel and cobalt bimetallic sulfide materials (NiCo-S) while these microspheres and nanosheets were composed of smaller nanoparticles. This unique structure endowed quick electron/ion transport and electrolyte penetration as well as abundant redox active sites, significantly facilitating electrochemical performance. The obtained NiCo-S-2 showed higher specific capacitance (1790.4 F g−1) than its precursor NiCo-MOF-2 and other molar ratios of counterparts. Using it as an positive electrode and activated carbon (AC) as negative electrode, the assembled asymmetric supercapacitor NiCo-S-2//AC also delivered a high specific capacitance of 114.4 F g−1 and big specific energy of 35.5 Wh kg−1 at 799.99 W kg−1.