Cobalt oxide composites derived from zeolitic imidazolate framework for high-performance supercapacitor electrode

Co-based zeolitic imidazolate framework (ZIF-67) was chosen as a precursor to synthesize the Co3O4 nanoparticles by annealing directly in air atmosphere at 450 and 750 °C. It is worth noting that the target temperature would play a critical role on the structure and texture of the obtaining Co3O4 nanoparticles. Serving as a supercapacitor electrode, the Co3O4 exhibits a remarkable specific capacitance of 706 and 543 Fg− 1 at a current density of 1 Ag− 1 in 1 mol/L KOH electrolyte, respectively. Moreover, the cycling stability is 71.5 and 70.6% after 1000 cycles. These results suggest that the electrochemical performance can be greatly enhanced by the well-controlled size and distribution of the Co3O4 nanoparticles.