Preparation and capacitance behaviors of cobalt oxide/graphene composites

Park, Soo‐Jin; Kim, Seok

doi:10.5714/cl.2012.13.2.130

Cited by 34 publications

(10 citation statements)

References 14 publications

(15 reference statements)

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“…Graphene addition has aided in circumventing the drawbacks faced by pristine cobalt oxide. Obtained specific capacitance is higher than rGO/Co 3 O 4 composite (291 F/g at 1 A/g) prepared by homogeneous incorporation of reduced graphene oxide sheets in cobalt oxide matrix reported by Wang et al [15], while Park et al [39] prepared Co 3 O 4 -GNS exhibited 396 F/g at 5 mV/s scan rate, Zhou et al [40] derived Co 3 O 4 -reduced graphene oxide scrolls demonstrated only 159.8 F/g at 5 mV/s scan rate and rapid microwave assisted synthesized graphene nanosheet/Co 3 O 4 composite prepared by J. Yan et al shows 243.2 F/g at 10 mV/s in 6 M KOH electrolyte [41]. High capacitance was due to the synergistic combination of good electro-activeness of cobalt oxide and high electrical conductivity of graphene nanosheets.…”

Section: Morphological Studiesmentioning

confidence: 83%

Cobalt oxide (Co3O4)/graphene nanosheets (GNS) composite prepared by novel route for supercapacitor application

Naveen

Manimaran

Selvasekarapandian

2015

J Mater Sci: Mater Electron

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Cobalt oxide (Co 3 O 4 )-graphene nanosheets (GNS) composite was prepared using a novel route. Room temperature prepared graphite oxide was exfoliated at low temperature and subsequently reduced to GNS by chemical method. Successful compound formation was confirmed and structural details were obtained from XRD studies. Cobalt oxide was found to crystallize in spinel fcc structure with average crystallite size of 9 nm in the composite. FTIR and XPS study confirms the removal of oxygen containing functional group in reduced graphene and spinel formation of cobalt oxide in the composite. Raman spectra depict the reestablishment of sp 2 conjugated network of carbon atoms, on reduction to graphene. FESEM images reveal the nanosheet like morphology of the graphene being retained in the composite and promoting ion diffusion channels. Electrochemical characterization discloses the pseudocapacitive behaviour of the composite material. Higher specific capacitance of 650 F/g was exhibited by GNS-Co 3 O 4 at 5 mV/s scan rate. Symmetrical supercapacitor fabricated using GNS-Co 3 O 4 demonstrated superior power characteristics. Graphene in the composite has substantially increased the electron and ion transport in the electrode material leading to enhanced performance.

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Section: Morphological Studiesmentioning

confidence: 83%

Cobalt oxide (Co3O4)/graphene nanosheets (GNS) composite prepared by novel route for supercapacitor application

Naveen

Manimaran

Selvasekarapandian

2015

J Mater Sci: Mater Electron

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“…Graphene, a carbon material with a two-dimensional nanostructure, has attracted a great deal of attention because of its high surface area, electrical conductivity, optimal mechanical stiffness, and high chemical stability [1][2][3]. In electrochemical measurements, multilayer graphene (from two to ten or more) is considered to be the promising electrode material for supercapacitors [4].…”

Section: Introductionmentioning

confidence: 99%

Capacitance behaviors of Polyaniline/Graphene Nanosheet Composites Prepared by Aniline Chemical Polymerization

Kim¹,

Park²,

Kim³

2013

Carbon letters

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In this study, polyaniline (PANI)/graphene nanosheet (GNS) composites were synthesized through chemical oxidation polymerization by changing the weight ratio of aniline monomers. To examine the morphological structure of the composites, scanning electron microscopy and transmission electron microscopy (TEM) were conducted. TEM results revealed that fibril-like PANI with a diameter of 50 nm was homogeneously coated on the surface of the GNS. The electrochemical properties of the composites were studied by cyclic voltammetry in 1 M H 2 SO 4 electrolyte. Among the prepared samples, the PANI/GNS (having 40 wt% aniline content) showed the highest specific capacitance, 528 Fg -1 , at 10 mVs -1 . The improved performance was attributed to the GNS, which provides a large number of active sites and good electrical conductivity. The resulting composites are promising electrode materials for high capacitative supercapacitors.

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“…Which shows specific capacitances of 273 F/g at a charge‐discharge density of 0.5 A/g 56 . The carbon coated cobalt oxide electrode materials reported by Kumar et al 57 exhibit a specific capacitance of 395 F/g at a scan rate of 5 mV/s and 90% capacitance retention over 2,000 cycles 57 ; cobalt oxide (Co 3 O 4 )/graphene composites 58 exhibited similar specific capacitance values (396 F/g). By adopting thermal reduction process, Ramesh et al 59 utilized equimolar stannous and cobalt precursor solutions with N‐doped graphene oxides to afford SnO 2 @Co 3 O 4 /NGO composites.…”

Section: Resultsmentioning

confidence: 83%

Ball‐milling route to design hierarchical nanohybrid cobalt oxide structures with cellulose nanocrystals interface for supercapacitors

Palem

Shimoga

Rabani

et al. 2022

Intl J of Energy Research

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Summary Nanocellulose materials are promising sustainable and environmentally friendly candidates for green and renewable energy storage applications. Herein, hierarchical Co3O4@CNC nanohybrid structure was fabricated in conjunction with cobalt acetate tetrahydrate and cellulose nanocrystals (CNC) as a bio‐carbon source using green ball‐milling pathway for the first time. For comparison, pristine Co3O4 nanostructure was prepared using a similar method without adding CNC. The structural and morphological characteristics of nanohybrid composites were investigated using X‐ray diffractometer (XRD), Raman, X‐ray photoelectron spectroscopy (XPS), Fourier‐transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Brunauer‐Emmett‐Teller (BET) techniques. Furthermore, the electrochemical properties of the nanohybrid composites evaluated using cyclic voltammetry (CV), Galvanostatic Charge‐Discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The hierarchical Co3O4@CNC nanohybrid electrode showed the highest specific capacitance of 396 F/g that of pristine Co3O4 nanostructure electrode (was 268 F/g) at a current density of 1.0 A/g for a three‐electrode assembly. The hierarchical Co3O4@CNC nanohybrid electrode showed appreciable capacitive behavior with 96% cyclic retention even after 5,000 cycles at 1.0 A/g with energy density of 12.5 Wh k−1 at a power density of 230.5 W k−1. Thus, it is suitable for improving and/or designing active electrocatalysts for enhanced supercapacitor applications.

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Preparation and capacitance behaviors of cobalt oxide/graphene composites

Cited by 34 publications

References 14 publications

Cobalt oxide (Co3O4)/graphene nanosheets (GNS) composite prepared by novel route for supercapacitor application

Cobalt oxide (Co3O4)/graphene nanosheets (GNS) composite prepared by novel route for supercapacitor application

Capacitance behaviors of Polyaniline/Graphene Nanosheet Composites Prepared by Aniline Chemical Polymerization

Ball‐milling route to design hierarchical nanohybrid cobalt oxide structures with cellulose nanocrystals interface for supercapacitors

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