LAUSR

Abstract A cost effective novel carbon quantum dots/Ce-doped nickel oxide (CQDs/Ce-NiO) nanocomposite was synthesized via hydrothermal route. An exceptional BET surface area of 731 m2 g−1 and mesoporosity (∼17 nm) was estimated. In three-electrode system an excellent electrochemical behaviour was demonstrated by CQDs/Ce-NiO nanocomposite with high specific capacitance of ∼2487 F g-1 by cyclic voltammograms at a scan rate of 5 mV s-1 and ∼2513 F g-1 by galvanostatic charge-discharge at a current density of 0.5 A g-1 in 6M KOH electrolyte. This may be owing to elegant redox activity of Ce3+/Ce4+ ions and high conductivity of CQDs. The capacitance retention was found ∼97 % after 2000 GCD cycles.