Precursor molecules as citric acid, ascorbic acid and imidazole were added to aqueous dispersions consisting of graphene oxide (GO) platelets and NiO nanoparticles, submitted to UV laser irradiation. The precursor molecules determine the reduction degrees and nitrogen doping of GO platelets transferred to the substrates surface. The nitrogen doped, highly reduced GO/NiO electrodes exhibit enhanced storage capacity and high cycling stability.
Fabrication of graphene-based electrochemical capacitors through reactive inverse matrix assisted pulsed laser evaporation
Ángel Pérez del Pino, Mohamed Ahmed Ramadan, Pablo Garcia Lebière, Raluca Ivan, Constantin Logofatu, Ibraheem Yousef, Enikö György
Applied Surface Science 484, 245-256, 2019
Figure: (a) Assembled device. (b) Galvanostatic charge-discharge curves of symmetric GO-NiO-imidazole device at different current densities. (c) Areal capacitance at different current densities, from galvanostatic charge-discharge data. (d) Areal capacitance at different sweep rates calculated from cyclic voltammetry (CV) data. Inset: CV loop obtained at 100 mV s-1 from asymmetric GO-imi/GO-NiO-imi (-/+) device. (e) Ragone plot of the assembled devices. (f) Capacitance retention and coulombic efficiency (inset) of the devices.