Single step assemble of cerium oxide embellished on layered graphene oxide: An efficacious electrode for supercapacitors and hydrogen evolution reaction

[Display omitted] •Nanostructured novel CeO2/GO were developed by single step method.•Nanocomposites produces the best electrochemical performances than individuals.•The composite materials works as novel electrocatalyst in both the Supercapacitor and OER applications.•Nanocomposites material fabricated symmetric device produces considerable specific capacitance (Cs), specific energy (SE), specific power (SP) values, along with acceptable cycle life. Single step hydrothermally synthesized the stable cerium oxide (CeO2) nanorods decorated on layered surface of graphene oxide (GO) flakes. The crystal surface structure of novel CeO2/GO nanocomposites were analysed by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET). Electrochemical behavior of the CeO2, GO and nanocomposites were explored from cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements using as active materials of the electrode. CeO2/GO nanocomposites displays higher specific capacitance (Cs, 616 Fg−1) than those of individuals at low scan rate of 2 mVs−1 by CV studies. Nanocomposites has good stability by exhibiting 82 % of capacitive retention after 10 k cycles at 10 Ag−1. Symmetric device were fabricated using nanocomposite materials for both anode and cathode. The device produces a considerable Cs, specific energy (SE), specific power (SP) values such as 55.3 Fg-1, 23.1 Whkg−1 and 5088 Wkg−1 respectively. Using symmetric device, continued the cycle life studies at 10 Ag−1 for 5 k cycles, and exhibited a capacitance retention of 82 %. With a low overpotential of 112 mV, a small Tafel slope of 77.46 mV dec-1, and long-term stability, the composites showed better HER performance.