Facile and green synthesis of Co3O4 nanoplates/graphene nanosheets composite for supercapacitor

Wang, Xiwen; Liu, Suqin; Wang, Haiyan; Tu, Feiyue; Fang, Dong; Li, Yanhua

doi:10.1007/s10008-012-1744-1

Cited by 84 publications

(32 citation statements)

References 51 publications

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“…22,33 As GO covered the Co(OH) 2 nanoplates, the intensity of the XRD peaks decreased ( Figure 9-1c), implying that the adsorption of GO disturbed the surface of Co(OH) 2 . 38 The oxidation of the Co(OH) 2 surface into Co 3 O 4 , caused by GO, is in good agreement with the XRD and the SAED analyses. After 1000 cycles, the XRD pattern of Figure 9-1d could no longer be matched to α-Co(OH) 2 but was indexed as the γ-CoOOH phase.…”

Section: Analyses Of Nanostructures By Tem Xrd and Raman Spectroscopysupporting

confidence: 78%

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

2015

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We synthesized binder-free Co(OH)2 nanocrystals on nickel electrodes by the ammonia transfer method in an aqueous solution and kinetically-controlled their thickness and height to enhance the capacitance through the facile diffusion of electrolytes in the nanocrystals. As thinner Co(OH)2 films were developed, the specific capacitance increased up to 1260 F g(-1) at a current density of 10 A g(-1). A thin layer of graphene oxide (GO) was used to wrap the Co(OH)2 nanocrystals to create a pseudocapacitor with high specific capacitance and good cyclic stability. This synthetic strategy enabled us to maximize the electrochemical cell performance, reaching a specific capacitance of 2710 F g(-1) under 10 A g(-1). The GO coating provides an effective method to increase adhesion on the nickel electrodes and to reduce the decomposition of Co(OH)2 during the charge-discharge process under high pH conditions. The prepared GO/Co(OH)2 nanocomposite layers provided not only high electron mobility but also ionic conductivity, especially when operated at a high current density.

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Section: Analyses Of Nanostructures By Tem Xrd and Raman Spectroscopysupporting

confidence: 78%

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

2015

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“…a show characteristic Raman peaks of Co 3 O 4 in all the samples synthesized from PVA14000 at 192, 469, 510, 609, and 669 cm −1 , and Fig. b shows the same for samples synthesized from PVA125000 at 192, 462,510, 608, and 660 cm −1 . In PVA14000 samples, it was observed that the peak intensity for the aforementioned Co 3 O 4 peaks increased from ASPV14 to 300PV14 to 500PV14 and then decreased in 800PV14.…”

Section: Resultsmentioning

confidence: 72%

Role of PVA in synthesis of nano Co₃O₄‐decorated graphene oxide

Jogdand

Das

Dhayagude

et al. 2015

Polymers for Advanced Techs

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Polymeric materials have been found to be ideal candidates for the synthesis of organic–inorganic nanomaterials. We have obtained Co3O4‐decorated graphene oxide (GO) nanocomposites by a simple polymer combustion method. Polyvinyl alcohol (PVA) of two different molecular weights, 14,000 and 125,000, was used for the synthesis. The pristine sample was annealed at 300, 500, and 800°C. PVA has played an important role in the formation of GO and Co3O4 nanoparticles. Synthesized Co3O4–GO nanocomposites were characterized by X‐ray diffraction, Fourier transform infrared, Raman, electron paramagnetic resonance, transmission electron microscopy, and vibrating sample magnetometry. Reflection peaks at 12° and 37° in an X‐ray study confirm the formation of Co3O4–GO. Raman study validates the presence of GO in nanocomposites of Co3O4–GO. Room temperature ferromagnetism was observed in all annealed samples. The highest coercivity of 462 G was observed for 300°C annealed samples as compared with bulk Co3O4. On the basis of the results obtained, a mechanism of formation is proposed. Copyright © 2015 John Wiley & Sons, Ltd.

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“…4b, c. It is observed that the anodic peaks shift toward high potential and cathodic peaks shift negatively upon increasing the potential scan rate pointing to the quasi-reversible nature of the redox couples [20]. Also, the anodic and cathodic peak current densities for both electrodes are relatively similar, indicating that charge and the discharge occur reversibly at the electrode/ electrolyte interface.…”

Section: Cyclic Voltammogramsmentioning

confidence: 85%

Preparation and electrochemical performances of nanoporous/cracked cobalt oxide layer for supercapacitors

Gobal

Faraji

2014

Appl. Phys. A

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Nanoporous/cracked structures of cobalt oxide (Co 3 O 4 ) electrodes were successfully fabricated by electroplating of zinc-cobalt onto previously formed TiO 2 nanotubes by anodizing of titanium, leaching of zinc in a concentrated alkaline solution and followed by drying and annealing at 400°C. The structure and morphology of the obtained Co 3 O 4 electrodes were characterized by X-ray diffraction, EDX analysis and scanning electron microscopy. The results showed that the obtained Co 3 O 4 electrodes were composed of the nanoporous/cracked structures with an average pore size of about 100 nm. The electrochemical capacitive behaviors of the nanoporous Co 3 O 4 electrodes were investigated by cyclic voltammetry, galvanostatic charge-discharge studies and electrochemical impedance spectroscopy in 1 M NaOH solution. The electrochemical data demonstrated that the electrodes display good capacitive behavior with a specific capacitance of 430 F g -1 at a current density of 1.0 A g -1 and specific capacitance retention of ca. 80 % after 10 days of being used in electrochemical experiments, indicating to be promising electroactive materials for supercapacitors. Furthermore, in comparison with electrodes prepared by simple cathodic deposition of cobalt onto TiO 2 nanotubes(without dealloying procedure), the impedance studies showed improved performances likely due to nanoporous/cracked structures of electrodes fabricated by dealloying of zinc, which provide fast ion and electron transfer routes and large reaction surface area with the ensued fast reaction kinetics.

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Facile and green synthesis of Co3O4 nanoplates/graphene nanosheets composite for supercapacitor

Cited by 84 publications

References 51 publications

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

Role of PVA in synthesis of nano Co₃O₄‐decorated graphene oxide

Preparation and electrochemical performances of nanoporous/cracked cobalt oxide layer for supercapacitors

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Facile and green synthesis of Co3O4 nanoplates/graphene nanosheets composite for supercapacitor

Cited by 84 publications

References 51 publications

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

Nanostructured cobalt hydroxide thin films as high performance pseudocapacitor electrodes by graphene oxide wrapping

Role of PVA in synthesis of nano Co3O4‐decorated graphene oxide

Preparation and electrochemical performances of nanoporous/cracked cobalt oxide layer for supercapacitors

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Role of PVA in synthesis of nano Co₃O₄‐decorated graphene oxide