DNA-templated synthesis of nickel cobaltite oxide nanoflake for high-performance electrochemical capacitors

NiCo2O4 nanoflake composites were synthesized by using DNA molecules as templates via in-situ assembly and subsequent thermal treatment. The obtained NiCo2O4 composites were characterized by scanning electron microscopy, energy dispersive spectroscopy, X-ray powder diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy. Cyclic voltammetry and chronopotentiometry tests were used to investigate the electrochemical properties of the as-prepared composites. Superior performances with a good specific capacitance (1468 F/g), an extraordinary rate capability (64.9% capacity retention at 16 A/g) and an excellent cycling stability (85.5% retention after 5000 cycles) were achieved. The DNA templates were introduced as the binder of NiCo2O4 and as the conductive matrix to facilitate the electron transmission between electroactive materials and outside current collectors, which resulted in the excellent electrochemical performances of the synthesized NiCo2O4 composites. It is believed that our NiCo2O4 nanocomposites could be used as effective electrode materials for supercapacitors.