Tailoring the graphene framework by embedding Nb2O5 and silver nanoparticles for electrodes in energy storage applications.

• The graphene-based nanocomposites i.e. Nb 2 O 5 /GNs and Ag/GNs were prepared by Single-step hydrothermal methods. • The specific capacitance (Csp) of Nb 2 O 5 /GNs and Ag/GNs were calculated 603 Fg−1 and 810 Fg−1 at a different current density with the cyclic stability retention of 93.06 % and 97.02 % respectively. • Current–voltage (I–V) measurements of as-fabricated composite showed an improved conductivity due to synergetic effect. In this study, Nb 2 O 5 /GNs and Ag/GNs-based nanocomposites were synthesized via a facile single-step hydrothermal approach. Using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, fourier-transform infrared (FTIR) spectroscopy, and UV–vis spectroscopy, the morphology, functional groups, structure, and optical and electrical properties of the as-prepared materials were examined. XPS studies show the predominant signal at 284.8 eV is attributed to the sp2 carbon atoms (C 1) that comprise graphitic areas, indicating that the majority of the C atoms are arranged in a honeycomb lattice. FTIR spectrum confirms bonding, such as C O, C H 2 , C O, C C, O H, Ag O, and Nb O Nb in the nanocomposite. Further, the specific capacitance (Csp) of the Nb 2 O 5 /GNs and Ag/GNs was calculated 603 Fg−1 and 810 Fg−1 at different current densities, The Nb 2 O 5 /GNs exhibit 109 Wh/kg and 2180 W/kg energy and power density, respectively. However, the Ag/GNs electrode exhibited an energy density of 145.8 Wh/kg and a power density of 3645 W/kg, with cyclic stability retentions of 93.06 % and 97.02 %, respectively. The capacitance retention finished at 1000 cycles. Moreover, the achieved resistance from the I– V characteristics curve shows enhanced electrical conductivity of synthesized nanocomposites. These results suggested that the materials can have bright future in next-generation energy storage devices. [Display omitted] [ABSTRACT FROM AUTHOR]