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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.


Related in: MedlinePlus

Supercapacitive performances of HCNs.(a) CV curves at different sweep rates and (b) galvanostatic charge–discharge curves under various current densities for HCN-900-10H5R. (c) Specific capacitances and (d) capacitance retention ratios of HCN-900-10H5R (red) and AC (black). (e) Electrochemical impedance spectra of HCN-900-10H5R (red) and AC (black). (f) Long-term cycle stability over 5,000 cycles for HCN-900-10H5R at current density of 1 A g−1; the inset shows the curves for the first and last three cycles.
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f5: Supercapacitive performances of HCNs.(a) CV curves at different sweep rates and (b) galvanostatic charge–discharge curves under various current densities for HCN-900-10H5R. (c) Specific capacitances and (d) capacitance retention ratios of HCN-900-10H5R (red) and AC (black). (e) Electrochemical impedance spectra of HCN-900-10H5R (red) and AC (black). (f) Long-term cycle stability over 5,000 cycles for HCN-900-10H5R at current density of 1 A g−1; the inset shows the curves for the first and last three cycles.

Mentions: Electric double-layer capacitors (EDLCs) or supercapacitors, featured by the high power density, rapid charging period and long-cycling life, represent an emerging class of power sources for portable electronic devices6740. It remains a long-standing goal to develop carbon electrodes having both high capacitance, strongly related to the availability of ion-accessible micropores, and high ion transport rate, closely associated with the availability of meso-/macropores and the size of carbon particles114142. In this respect, HCNs will be very promising electrode materials for EDLCs because they bear well-developed porous structures, well-defined hollow nanosphereric morphology and nitrogen-containing functional groups. As a proof-of-concept demonstration, the HCN-900-10H5R was evaluated with a two-electrode symmetrical cell in 6 M KOH aqueous electrolyte. The cyclic voltammetry (CV) curves exhibit rectangular shapes and the galvanostatic charge–discharge curves display typical triangular profiles (Fig. 5a,b). These results clearly highlight the superior supercapacitive performances, benefitting from their unique porous nanostructures. The tremendous small-sized nanopores on the carbon shells can strongly adsorb a large quantity of electrolyte ions for high capacitances, whereas the uniform nanospheres (<100 nm) with hollow cores can significantly decrease the ion diffusion length (half of the shell thickness, for example, 12 nm for HCN-900-10H5R; Supplementary Fig. 2; ref. 43). Moreover, the nitrogen-containing functional groups are also beneficial to the superior supercapacitive performances by improving electrolyte wettability and electrical conductivity and providing additional pseudocapacitance67. In sharp contrast, the nanopores in the activated carbon AC are mainly located on the surface of micron-/millimetre-scaled carbon particles (for example, >10 μm; ref. 41). This causes greatly retarded mass transfer, and thereby places a great barrier for applications in high power EDLCs. Therefore, the CV curves of AC distort much seriously, especially with increasing the sweeping rate (Supplementary Fig. 10), and the galvanostatic discharge curves present a notable voltage drop at high current densities (Supplementary Fig. 11).


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)

Supercapacitive performances of HCNs.(a) CV curves at different sweep rates and (b) galvanostatic charge–discharge curves under various current densities for HCN-900-10H5R. (c) Specific capacitances and (d) capacitance retention ratios of HCN-900-10H5R (red) and AC (black). (e) Electrochemical impedance spectra of HCN-900-10H5R (red) and AC (black). (f) Long-term cycle stability over 5,000 cycles for HCN-900-10H5R at current density of 1 A g−1; the inset shows the curves for the first and last three cycles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4490369&req=5

f5: Supercapacitive performances of HCNs.(a) CV curves at different sweep rates and (b) galvanostatic charge–discharge curves under various current densities for HCN-900-10H5R. (c) Specific capacitances and (d) capacitance retention ratios of HCN-900-10H5R (red) and AC (black). (e) Electrochemical impedance spectra of HCN-900-10H5R (red) and AC (black). (f) Long-term cycle stability over 5,000 cycles for HCN-900-10H5R at current density of 1 A g−1; the inset shows the curves for the first and last three cycles.
Mentions: Electric double-layer capacitors (EDLCs) or supercapacitors, featured by the high power density, rapid charging period and long-cycling life, represent an emerging class of power sources for portable electronic devices6740. It remains a long-standing goal to develop carbon electrodes having both high capacitance, strongly related to the availability of ion-accessible micropores, and high ion transport rate, closely associated with the availability of meso-/macropores and the size of carbon particles114142. In this respect, HCNs will be very promising electrode materials for EDLCs because they bear well-developed porous structures, well-defined hollow nanosphereric morphology and nitrogen-containing functional groups. As a proof-of-concept demonstration, the HCN-900-10H5R was evaluated with a two-electrode symmetrical cell in 6 M KOH aqueous electrolyte. The cyclic voltammetry (CV) curves exhibit rectangular shapes and the galvanostatic charge–discharge curves display typical triangular profiles (Fig. 5a,b). These results clearly highlight the superior supercapacitive performances, benefitting from their unique porous nanostructures. The tremendous small-sized nanopores on the carbon shells can strongly adsorb a large quantity of electrolyte ions for high capacitances, whereas the uniform nanospheres (<100 nm) with hollow cores can significantly decrease the ion diffusion length (half of the shell thickness, for example, 12 nm for HCN-900-10H5R; Supplementary Fig. 2; ref. 43). Moreover, the nitrogen-containing functional groups are also beneficial to the superior supercapacitive performances by improving electrolyte wettability and electrical conductivity and providing additional pseudocapacitance67. In sharp contrast, the nanopores in the activated carbon AC are mainly located on the surface of micron-/millimetre-scaled carbon particles (for example, >10 μm; ref. 41). This causes greatly retarded mass transfer, and thereby places a great barrier for applications in high power EDLCs. Therefore, the CV curves of AC distort much seriously, especially with increasing the sweeping rate (Supplementary Fig. 10), and the galvanostatic discharge curves present a notable voltage drop at high current densities (Supplementary Fig. 11).

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