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Facile synthesis of ultrahigh-surface-area hollow carbon nanospheres for enhanced adsorption and energy storage.

Xu F, Tang Z, Huang S, Chen L, Liang Y, Mai W, Zhong H, Fu R, Wu D - Nat Commun (2015)

Bottom Line: Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions.The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries.The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

View Article: PubMed Central - PubMed

Affiliation: Materials Science Institute, PCFM Lab and GDHPPC Lab, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.

ABSTRACT
Exceptionally large surface area and well-defined nanostructure are both critical in the field of nanoporous carbons for challenging energy and environmental issues. The pursuit of ultrahigh surface area while maintaining definite nanostructure remains a formidable challenge because extensive creation of pores will undoubtedly give rise to the damage of nanostructures, especially below 100 nm. Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions. The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries. The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

No MeSH data available.


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Structural characterizations of HCN/S nanocomposites.(a) SEM and (e) TEM images for HCN-900-10H5R/S; (b) bright-field TEM image and corresponding elemental mappings of (c) carbon and (d) sulphur for HCN-900-10H5R/S; (f) XRD patterns for HCN-900-10H5R/S (red), mixture of HCN-900-10H5R and S before melting infiltration (blue) and sulphur (black); (g) Raman spectra of HCN-900-10H5R/S (red), HCN-900-10H5R (blue) and sulphur (black). Scale bars, 500 nm (a), 200 nm (b) and 100 nm (e).
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f6: Structural characterizations of HCN/S nanocomposites.(a) SEM and (e) TEM images for HCN-900-10H5R/S; (b) bright-field TEM image and corresponding elemental mappings of (c) carbon and (d) sulphur for HCN-900-10H5R/S; (f) XRD patterns for HCN-900-10H5R/S (red), mixture of HCN-900-10H5R and S before melting infiltration (blue) and sulphur (black); (g) Raman spectra of HCN-900-10H5R/S (red), HCN-900-10H5R (blue) and sulphur (black). Scale bars, 500 nm (a), 200 nm (b) and 100 nm (e).

Mentions: Our HCNs can be also applied as high-performance cathode host materials to immobilize sulphur for Li–S batteries. Element sulphur as cathode possesses high theoretical capacity (1,675 mA hg−1) and energy density (2,567 Wh kg−1), much higher than those of conventional inorganic metal-based lithium-ion batteries44454647. However, several major issues have to be overcome before Li–S batteries can find their widespread practical application. They include poor conductivity of sulphur and discharge product Li2S, serious dissolution of intermediate polysulphides with a shuttling phenomenon, and large volumetric expansion (76%) upon lithiation4647. These problems result in poor cyclability, low coulombic efficiency and deteriorated rate capability. Motivated by the pioneer work by Nazar and colleagues48 using mesoporous carbon particles to encapsulate sulphur, exciting progress has recently been made in trapping polysulphide species by porous carbons. HCNs, in this respect, are particularly attracting as host materials for sulphur accommodation27495051. Sulphur could be encapsulated and sequestered in their conductive nanoporous shell, which is beneficial for enhancing charge transfer and accommodating volume expansion during redox cycling. Moreover, the sulphur content in nanocomposites can be controlled by choosing HCNs with different pore volumes, so as to tailor the overall capacity (TGA curves; Supplementary Fig. 14). Melt-diffusion method is used to impregnate sulphur into the nanopores of HCNs. After sulphur impregnation, the SBET and pore volume of the resulting HCN-900-10H5R/S nanocomposite drastically decrease (Supplementary Fig. 15), and no any discernible sulphur particles is detected outside the HCN-900-10H5R (Fig. 6a,b,e). TEM images of the HCN-900-10H5R/S composite indicate that the hollow cores of HCN-900-10H5R are not occupied by sulphur (Fig. 6b,e), revealing that the majority of sulphur is impregnated into the nanopores of shells of HCN-900-10H5R. Elemental mapping images of C and S demonstrate the uniform distribution of sulphur (Fig. 6c,d). The diffraction signals assignable to crystalline sulphur disappear in the X-ray diffraction (XRD) profiles (Fig. 6f), and no signal below 500 cm−1 is found in HCN-900-10H5R/S in Raman spectra (Fig. 6g), further confirming that sulphur is in a homogeneously dispersed state48. The uniformly encapsulated sulphur exists in the form of elemental sulphur, judging from the almost unchanged peaks at 163.8 and 164.9 eV in X-ray photoelectron spectroscopy (XPS; Supplementary Fig. 16).


Facile synthesis of ultrahigh-surface-area hollow carbon nanospheres for enhanced adsorption and energy storage.

Xu F, Tang Z, Huang S, Chen L, Liang Y, Mai W, Zhong H, Fu R, Wu D - Nat Commun (2015)

Structural characterizations of HCN/S nanocomposites.(a) SEM and (e) TEM images for HCN-900-10H5R/S; (b) bright-field TEM image and corresponding elemental mappings of (c) carbon and (d) sulphur for HCN-900-10H5R/S; (f) XRD patterns for HCN-900-10H5R/S (red), mixture of HCN-900-10H5R and S before melting infiltration (blue) and sulphur (black); (g) Raman spectra of HCN-900-10H5R/S (red), HCN-900-10H5R (blue) and sulphur (black). Scale bars, 500 nm (a), 200 nm (b) and 100 nm (e).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4490369&req=5

f6: Structural characterizations of HCN/S nanocomposites.(a) SEM and (e) TEM images for HCN-900-10H5R/S; (b) bright-field TEM image and corresponding elemental mappings of (c) carbon and (d) sulphur for HCN-900-10H5R/S; (f) XRD patterns for HCN-900-10H5R/S (red), mixture of HCN-900-10H5R and S before melting infiltration (blue) and sulphur (black); (g) Raman spectra of HCN-900-10H5R/S (red), HCN-900-10H5R (blue) and sulphur (black). Scale bars, 500 nm (a), 200 nm (b) and 100 nm (e).
Mentions: Our HCNs can be also applied as high-performance cathode host materials to immobilize sulphur for Li–S batteries. Element sulphur as cathode possesses high theoretical capacity (1,675 mA hg−1) and energy density (2,567 Wh kg−1), much higher than those of conventional inorganic metal-based lithium-ion batteries44454647. However, several major issues have to be overcome before Li–S batteries can find their widespread practical application. They include poor conductivity of sulphur and discharge product Li2S, serious dissolution of intermediate polysulphides with a shuttling phenomenon, and large volumetric expansion (76%) upon lithiation4647. These problems result in poor cyclability, low coulombic efficiency and deteriorated rate capability. Motivated by the pioneer work by Nazar and colleagues48 using mesoporous carbon particles to encapsulate sulphur, exciting progress has recently been made in trapping polysulphide species by porous carbons. HCNs, in this respect, are particularly attracting as host materials for sulphur accommodation27495051. Sulphur could be encapsulated and sequestered in their conductive nanoporous shell, which is beneficial for enhancing charge transfer and accommodating volume expansion during redox cycling. Moreover, the sulphur content in nanocomposites can be controlled by choosing HCNs with different pore volumes, so as to tailor the overall capacity (TGA curves; Supplementary Fig. 14). Melt-diffusion method is used to impregnate sulphur into the nanopores of HCNs. After sulphur impregnation, the SBET and pore volume of the resulting HCN-900-10H5R/S nanocomposite drastically decrease (Supplementary Fig. 15), and no any discernible sulphur particles is detected outside the HCN-900-10H5R (Fig. 6a,b,e). TEM images of the HCN-900-10H5R/S composite indicate that the hollow cores of HCN-900-10H5R are not occupied by sulphur (Fig. 6b,e), revealing that the majority of sulphur is impregnated into the nanopores of shells of HCN-900-10H5R. Elemental mapping images of C and S demonstrate the uniform distribution of sulphur (Fig. 6c,d). The diffraction signals assignable to crystalline sulphur disappear in the X-ray diffraction (XRD) profiles (Fig. 6f), and no signal below 500 cm−1 is found in HCN-900-10H5R/S in Raman spectra (Fig. 6g), further confirming that sulphur is in a homogeneously dispersed state48. The uniformly encapsulated sulphur exists in the form of elemental sulphur, judging from the almost unchanged peaks at 163.8 and 164.9 eV in X-ray photoelectron spectroscopy (XPS; Supplementary Fig. 16).

Bottom Line: Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions.The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries.The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

View Article: PubMed Central - PubMed

Affiliation: Materials Science Institute, PCFM Lab and GDHPPC Lab, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.

ABSTRACT
Exceptionally large surface area and well-defined nanostructure are both critical in the field of nanoporous carbons for challenging energy and environmental issues. The pursuit of ultrahigh surface area while maintaining definite nanostructure remains a formidable challenge because extensive creation of pores will undoubtedly give rise to the damage of nanostructures, especially below 100 nm. Here we report that high surface area of up to 3,022 m(2) g(-1) can be achieved for hollow carbon nanospheres with an outer diameter of 69 nm by a simple carbonization procedure with carefully selected carbon precursors and carbonization conditions. The tailor-made pore structure of hollow carbon nanospheres enables target-oriented applications, as exemplified by their enhanced adsorption capability towards organic vapours, and electrochemical performances as electrodes for supercapacitors and sulphur host materials for lithium-sulphur batteries. The facile approach may open the doors for preparation of highly porous carbons with desired nanostructure for numerous applications.

No MeSH data available.


Related in: MedlinePlus