A new tetradecanuclear cobalt cluster [Co14(TC4A)3Cl3(Tz)12(H2O)6](OH)(DMF)14(CH3OH)6(H2O)4 (Abbr. Co14, H4TC4A = p-tert-Butylthiacalixarene, HTz = 1H-tetrazole) was obtained by the solvothermal reaction of CoCl2·6H2O, H4TC4A and Htz in DMF. The cluster featured the quadrilateral planar CoII4 units housing tri-capped trigonal Co12 clusters with two enclosed Co nanocages linked by Tz ligands. The uniform CoO/Co9S8@CN composite derived from direct annealing of Co14 clusters was obtained and characterized by XRD, EDS, XPS, and Raman spectra. The composite on nickel foam (CoO/Co9S8@CN/NF) was used as an electrode to fabricate supercapacitors with specific capacitances of 83.7% at 2 A g-1 and 70.0% at 5 A g-1 at 0.5 A g-1 (303.3 F g-1). The composite from Co14 precursor also shows high charge-discharge reversibility with a capacity retention of 96.3% and average columbic efficiency of 98.2% after 1000 cycles at 2.0 A g-1.
ASJC Scopus subject areas
- Inorganic Chemistry