Facile synthesis of NiCo2O4-reduced graphene oxide nanocomposites with improved electrochemical properties

Reduced graphene oxide-nickel cobaltite (RGO-NiCo2O4) nanocomposites have been successfully synthesized by a hydrothermal method with the assistance of Poly (diallyldimethylammonium chloride) (PDDA). PDDA is used as a reducing agent, capping agent and a stabilizer. The prepared RGO-NiCo2O4 nanocomposites have been thoroughly characterized by spectroscopic (Fourier-transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy) and thermogravimetric analysis. Microscopy techniques (scanning electron microscopy, transmission electron microscopy and atomic force microscopy) were employed to probe the morphological structures as well as to investigate the exfoliation of RGO sheets. The nanocomposites exhibited superior performance to NiCo2O4 as electrodes in pseudocapacitors with capacitance of 676.1 F/g. This is attributed to the increased electrical conductivity and the creation of new active sites due to the synergetic effect of RGO and NiCo2O4 nanoparticles.