Enhanced performance of NiMoO₄ nanoparticles and quantum dots and reduced nanohole graphene oxide hybrid for supercapacitor applications

Highlights: • Nanohole on graphene oxide promoted to form NiMoO₄ nanoparticles and quantum dots. • NiMoO₄@NHGO exhibited excellent specific capacitance and cycling stability. • Large surface area, high electrical conductivity and synergistic effect improved capacitance. - Abstract: NiMoO₄ nanoparticles and quantum dots were uniformly distributed on the surface of reduced nanohole graphene oxide (rNHGO). NiMoO₄@rNHGO exhibited a higher specific capacitance and better cycling stability than NiMoO₄@reduced graphene oxide (rGO), which were attributed to the large surface area and high electrical conductivity. NiMoO₄ nanoparticles and quantum dots (QDs) had high surface to volume ratio, which would not result in change in volume during the electro–chemical operation and induced better supercapacitor performance. Moreover, synergistic effect between NiMoO₄ and the rNHGO also improved undoubtedly high specific capacitance and cycle stability.