NiO nanoflakes grown on porous graphene frameworks as advanced electrochemical pseudocapacitor materials
2014; Elsevier BV; Volume: 259; Linguagem: Inglês
10.1016/j.jpowsour.2014.02.088
ISSN1873-2755
AutoresMeiling Huang, Changdong Gu, Xiang Ge, Xiuli Wang, J.P. Tu,
Tópico(s)Graphene research and applications
ResumoA NiO–graphene hybrid film with 3D hierarchically porous structure has been rationally designed and constructed through a series of controlled fabrication processes. Multilayered porous graphene sheet network with the pore size of several micrometers is created via a so-called “on-water spreading” method, which is facile, economical, efficient and scalable. Then, the cross-like NiO nanoflakes film is uniformly grown onto the porous graphene sheet framework by a chemical bath deposition. The NiO–graphene hybrid film exhibits specific capacitance of 540 F g−1 at 2 A g−1 with 80% capacitance retention after 2000 cycles in 2 M KOH aqueous solution, which is much higher than that achieved from the bare NiO nanoflakes film (370 F g−1, with 66% capacitance retention). Moreover, chronoamperometry and electrochemical impedance spectroscopy measurements reveal that the NiO–graphene hybrid demonstrates enhanced reaction kinetics with about only 50% of respond time for NiO/NiOOH reaction and 79% of charge-transfer resistance compared with those of the bare NiO film. The proposed strategy could offer an effective way to fabricate graphene-based electrode materials for applications in various energy-storage devices.
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