A Three-Dimensional Copper Coordination Polymer Constructed by 3-Methyl-1H-pyrazole-4-carboxylic Acid with Higher Capacitance for Supercapacitors

A three-dimensional (3D) copper-based coordination polymer, ([Cu(H2mpca)(tfbdc)], Cu-CP; H2mpca = 3-methyl-1H-pyrazole-4-carboxylic acid; H2tfbdc = 2,3,5,6-tetrafluoroterephthalic acid), has been synthesized and characterized by IR spectroscopy, thermogravimetric analysis, elemental analysis, and single-crystal X-ray diffraction. In Cu-CP, each Cu(II) ion is located in a triangular bipyramid geometry, and these Cu(II) ions are linked by tfbdc2– ligands to produce a 3D network. Variable-temperature magnetic susceptibility data display that weak antiferromagnetic interactions between the adjacent Cu (II) ions exist in Cu-CP. Cu-CP was evaluated as an electrode material for supercapacitors. It displayed a higher specific capacitance of 735 F g–1 in 1 M KOH solution at a current density of 1 A g–1 and remained at 375 F g–1 after 1500 cycles at 2 A g–1.