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Self-assembly formation of hollow Ni-Fe-O nanocage architectures by metal-organic frameworks with high-performance lithium storage.

Guo H, Li T, Chen W, Liu L, Qiao J, Zhang J - Sci Rep (2015)

Bottom Line: The stable cyclic performance is obtained for all rates from 1 C to 10 C.Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1).Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry Science and Engineering, Yunnan University, Kunming 650091,Yunnan, China.

ABSTRACT
A hollow hybrid Ni-Fe-O nanomaterial (NiFe2O4) is synthesized using a precursor of metal-organic frameworks through a simple and cost-effective method. The unique hollow nanocage structures shorten the length of Li-ion diffusion. The hollow structure offers a sufficient void space, which sufficiently alleviates the mechanical stress caused by volume change. Besides, the hybrid elements allow the volume change to take place in a stepwise manner during electrochemical cycle. And thus, the hierarchical hollow NiFe2O4 nanocage electrode exhibits extraordinary electrochemical performance. The stable cyclic performance is obtained for all rates from 1 C to 10 C. Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1). Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles. This strategy that derived from NMOFs may shed light on a new route for large-scale synthesis of hollow porous hybrid nanocages for energy storage, environmental remediation and other novel applications.

No MeSH data available.


FTIR spectra of hollow NiFe2O4 nanocages (b) and its precursor (a).
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f3: FTIR spectra of hollow NiFe2O4 nanocages (b) and its precursor (a).

Mentions: The crystallographic structure and phase purity of the precursor and as-synthesized hollow porous NiFe2O4 nanocages are analyzed by XRD, as shown in Fig. 2a,b. From Fig. 2a and compared the spectrum with standard one (JCPDS card no. 46–0908), it can be seen that the precursor Ni2Fe(CN)6 does not contain impurity. All the diffraction peaks of final products, shown in Fig. 2b, can be indexed to the monoclinic phase of NiFe2O4 (JCPDS card no. 10–0325) without impurity peaks, indicating a complete thermal conversion of the NMOF precursors into NiFe2O4 nanostructures. The FTIR spectrum images of the prepared hollow structured NiFe2O4 nanocage sample and its Ni2Fe(CN)6 precursor are shown in Fig. 3. The broad absorption peaks centered at ca. 3391 to 2357 cm−1 can be assigned to the stretching vibrations of the -OH group of absorbed water molecules and absorption of CO2 in the air. According to the spectrum of Ni2Fe(CN)6, the peaks from 1654 to 1601 cm−1 can be assigned to the bending vibrations of the water molecules; the spike of 2108 cm−1 is assigned to the stretching vibrations of the cyano group of precursor. These peaks are all disappeared in the spectrum of synthesized NiFe2O4 samples, indicating that these groups have decomposed after the calcinations. The strongest broad peaks in the range of 992 to 500 cm−1 are contributed from the bands of metal-oxide29.


Self-assembly formation of hollow Ni-Fe-O nanocage architectures by metal-organic frameworks with high-performance lithium storage.

Guo H, Li T, Chen W, Liu L, Qiao J, Zhang J - Sci Rep (2015)

FTIR spectra of hollow NiFe2O4 nanocages (b) and its precursor (a).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562299&req=5

f3: FTIR spectra of hollow NiFe2O4 nanocages (b) and its precursor (a).
Mentions: The crystallographic structure and phase purity of the precursor and as-synthesized hollow porous NiFe2O4 nanocages are analyzed by XRD, as shown in Fig. 2a,b. From Fig. 2a and compared the spectrum with standard one (JCPDS card no. 46–0908), it can be seen that the precursor Ni2Fe(CN)6 does not contain impurity. All the diffraction peaks of final products, shown in Fig. 2b, can be indexed to the monoclinic phase of NiFe2O4 (JCPDS card no. 10–0325) without impurity peaks, indicating a complete thermal conversion of the NMOF precursors into NiFe2O4 nanostructures. The FTIR spectrum images of the prepared hollow structured NiFe2O4 nanocage sample and its Ni2Fe(CN)6 precursor are shown in Fig. 3. The broad absorption peaks centered at ca. 3391 to 2357 cm−1 can be assigned to the stretching vibrations of the -OH group of absorbed water molecules and absorption of CO2 in the air. According to the spectrum of Ni2Fe(CN)6, the peaks from 1654 to 1601 cm−1 can be assigned to the bending vibrations of the water molecules; the spike of 2108 cm−1 is assigned to the stretching vibrations of the cyano group of precursor. These peaks are all disappeared in the spectrum of synthesized NiFe2O4 samples, indicating that these groups have decomposed after the calcinations. The strongest broad peaks in the range of 992 to 500 cm−1 are contributed from the bands of metal-oxide29.

Bottom Line: The stable cyclic performance is obtained for all rates from 1 C to 10 C.Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1).Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles.

View Article: PubMed Central - PubMed

Affiliation: School of Chemistry Science and Engineering, Yunnan University, Kunming 650091,Yunnan, China.

ABSTRACT
A hollow hybrid Ni-Fe-O nanomaterial (NiFe2O4) is synthesized using a precursor of metal-organic frameworks through a simple and cost-effective method. The unique hollow nanocage structures shorten the length of Li-ion diffusion. The hollow structure offers a sufficient void space, which sufficiently alleviates the mechanical stress caused by volume change. Besides, the hybrid elements allow the volume change to take place in a stepwise manner during electrochemical cycle. And thus, the hierarchical hollow NiFe2O4 nanocage electrode exhibits extraordinary electrochemical performance. The stable cyclic performance is obtained for all rates from 1 C to 10 C. Even when the current reaches 10 C, the capacity can also arrive at 652 mAhg(-1). Subsequently, a specific capacity of ca. 975 mAhg(-1) is recovered when the current rate reduces back to 1 C after 200 cycles. This strategy that derived from NMOFs may shed light on a new route for large-scale synthesis of hollow porous hybrid nanocages for energy storage, environmental remediation and other novel applications.

No MeSH data available.