One-step synthesis of high-quality N-doped graphene/Fe₃O₄hybrid nanocomposite and its improved supercapacitor performances

Abstract

A series of high-quality N-doped graphene (N-graphene)/Fe3O4 nanocomposites were readily obtained by a simple one-pot hydrothermal method under mild conditions.

Facile synthesis of the N-doped graphene/nickel oxide with enhanced electrochemical performance for rechargeable lithium-ion batteries

“…Especially, at the high current density of 2 A g À1 , a higher discharge capacity of NGr-NiO-M can reach 833 mAh g À1 than that of NGrNiO. All these results are superior to the previous mentioned literature [33,52,53], which may be the effect of microwave treatment by promoting the conductivity of composites and removing the oxygen-containing functional groups on the surface of the nitrogen-doped graphene [34]. Besides, the galvanostatic charge/ discharge cycling performance of the NGr-NiO-M electrode shown in Fig.…”

“…So the highresolution spectrum of N 1s (inset in Fig. 5 (d)) reveals the existence of the form of pyridinic N (398 eV) [34]. It is convinced that the nitrogen doped in the graphene sheets may come from the urea during the hydrothermal process [34,48].…”

“…The reversible capacity can steadily reach about 1095 mAh g À1 (the NGr-NiO, graphene-NiO, bare NiO and graphene are about 930 mAh g À1 , 809 mAh g À1 , 195 mAh g À1 and 296 mAh g À1 , respectively) and the Coulombic efficiency can nearly achieve 100% after 100 cycles. This improved performance may be as the result of (1) the unique structure of the nanocomposites, graphene can be used as a barrier to prevent the aggregation of NiO nanoparticles and a buffer to against the volume changes of metal oxide nanoparticles during the charging-discharging process; (2) the two-dimensional conductive network established by graphene may be greatly beneficial to the enhancement of capacity; (3) the NiO nanoparticles uniformly distributed on the grahene, which can restrain the restacking of graphene and improve the conductivity of the nanocomposites electrodes; (4) the nitrogen which doped in the graphene may enhance the conductivity of graphene sheets and capacity of the electrodes [23,34].…”

Laser-induced chemical transformation of graphene oxide–iron oxide nanoparticles composites deposited on polymer substrates

“…Thus, the support of rGO-Fe 3 O 4 composites on polymer substrates is desirable. Recent works point to the improvement of rGO and rGO-Fe 3 O 4 materials' functional properties, such as oxygen reduction reaction yield and supercapacitor performance, after the nitrogen doping of the graphene structure [14][15][16] due to the modulation of optical and electronic properties [17]. Particularly, doping of graphene structure by graphitic (substitutional) nitrogen provokes a n-type behavior, whereas pyridinic and pyrrolic N may lead to a p-type performance, instead.…”

Synthesis of reduced graphene oxide wrapped-copper sulfide hollow spheres as electrode material for supercapacitor

“…Generally, supercapacitors have two energy storage mechanisms: fast surface redox reaction (pseudocapacitors) and ion adsorption at the electrode/electrolyte interface (electrochemical double layer capacitors, EDLCs) [4,5]. Thereinto, pseudocapacitors have attracted more attention due to their higher power densities and capacitance [6]. RuO 2 and other transition metal oxides have been widely used as electrode material in pseudocapacitors due to their high specific capacitance [7].…”