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Electrospun interconnected Fe-N/C nanofiber networks as efficient electrocatalysts for oxygen reduction reaction in acidic media.

Wu N, Wang Y, Lei Y, Wang B, Han C, Gou Y, Shi Q, Fang D - Sci Rep (2015)

Bottom Line: One-dimensional electrospun nanofibers have emerged as a potential candidate for high-performance oxygen reduction reaction (ORR) catalysts.Intriguingly, the resulting Fe-N/C NNs exhibit 34% higher peak current density and superior durability than generic Fe-N/C ones with similar microstructure and chemical compositions.The higher electroactivity is mainly due to the more effective electron transport between the interconnected nanofibers.

View Article: PubMed Central - PubMed

Affiliation: Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha 410073, P.R. China.

ABSTRACT
One-dimensional electrospun nanofibers have emerged as a potential candidate for high-performance oxygen reduction reaction (ORR) catalysts. However, contact resistance among the neighbouring nanofibers hinders the electron transport. Here, we report the preparation of interconnected Fe-N/C nanofiber networks (Fe-N/C NNs) with low electrical resistance via electrospinning followed by maturing and pyrolysis. The Fe-N/C NNs show excellent ORR activity with onset and half-wave potential of 55 and 108 mV less than those of Pt/C catalyst in 0.5 M H2SO4. Intriguingly, the resulting Fe-N/C NNs exhibit 34% higher peak current density and superior durability than generic Fe-N/C ones with similar microstructure and chemical compositions. Additionally, it also displays much better durability and methanol tolerance than Pt/C catalyst. The higher electroactivity is mainly due to the more effective electron transport between the interconnected nanofibers. Thus, our findings provide a novel insight into the design of functional electrospun nanofibers for the application in energy storage and conversion fields.

No MeSH data available.


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N2 sorption isotherms and corresponding pore size distribution curves (inset) for (a) Fe-N/C NNs and (b) Fe-N/C NMs.
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f3: N2 sorption isotherms and corresponding pore size distribution curves (inset) for (a) Fe-N/C NNs and (b) Fe-N/C NMs.

Mentions: Fe-N/C catalysts were further investigated by N2 adsorption-desorption techniques. Brunauer-Emmett-Teller (BET) surface areas for Fe-N/C NNs and Fe-N/C NMs are 159.9 and 217.1 m2 g−1, respectively (Fig. 3). Besides, the remarkable hysteresis loops at the relative pressure range from 0.5 to 1.0 present the mesoporous nature existing in these two samples, which is favourable to the adsorption and transportation of oxygen3435. Furthermore, the electrochemical double-layer capacitance (Cdl), which is considered to be positively proportional to electrochemical active surface area, is determined by applying cyclic voltammograms (CVs) at a series of scan rate36. As shown in Fig. S5†, the Cdl of Fe-N/C NNs is 9.7 mF cm−2, which is larger than that of Fe-N/C NMs (8.2 mF cm−2). The higher Cdl will provide more effective active sites to enhance the eletrocatalytic performance for Fe-N/C NNs. In addition, the electrical conductivity of Fe-N/C NNs and Fe-N/C NMs measured by two-point probe method (Fig. S6†) is 20.2 and 8.5 S cm−1, respectively. This displays that the interconnected framework could provide multidimensional pathways to facilitate electron transport.


Electrospun interconnected Fe-N/C nanofiber networks as efficient electrocatalysts for oxygen reduction reaction in acidic media.

Wu N, Wang Y, Lei Y, Wang B, Han C, Gou Y, Shi Q, Fang D - Sci Rep (2015)

N2 sorption isotherms and corresponding pore size distribution curves (inset) for (a) Fe-N/C NNs and (b) Fe-N/C NMs.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663764&req=5

f3: N2 sorption isotherms and corresponding pore size distribution curves (inset) for (a) Fe-N/C NNs and (b) Fe-N/C NMs.
Mentions: Fe-N/C catalysts were further investigated by N2 adsorption-desorption techniques. Brunauer-Emmett-Teller (BET) surface areas for Fe-N/C NNs and Fe-N/C NMs are 159.9 and 217.1 m2 g−1, respectively (Fig. 3). Besides, the remarkable hysteresis loops at the relative pressure range from 0.5 to 1.0 present the mesoporous nature existing in these two samples, which is favourable to the adsorption and transportation of oxygen3435. Furthermore, the electrochemical double-layer capacitance (Cdl), which is considered to be positively proportional to electrochemical active surface area, is determined by applying cyclic voltammograms (CVs) at a series of scan rate36. As shown in Fig. S5†, the Cdl of Fe-N/C NNs is 9.7 mF cm−2, which is larger than that of Fe-N/C NMs (8.2 mF cm−2). The higher Cdl will provide more effective active sites to enhance the eletrocatalytic performance for Fe-N/C NNs. In addition, the electrical conductivity of Fe-N/C NNs and Fe-N/C NMs measured by two-point probe method (Fig. S6†) is 20.2 and 8.5 S cm−1, respectively. This displays that the interconnected framework could provide multidimensional pathways to facilitate electron transport.

Bottom Line: One-dimensional electrospun nanofibers have emerged as a potential candidate for high-performance oxygen reduction reaction (ORR) catalysts.Intriguingly, the resulting Fe-N/C NNs exhibit 34% higher peak current density and superior durability than generic Fe-N/C ones with similar microstructure and chemical compositions.The higher electroactivity is mainly due to the more effective electron transport between the interconnected nanofibers.

View Article: PubMed Central - PubMed

Affiliation: Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha 410073, P.R. China.

ABSTRACT
One-dimensional electrospun nanofibers have emerged as a potential candidate for high-performance oxygen reduction reaction (ORR) catalysts. However, contact resistance among the neighbouring nanofibers hinders the electron transport. Here, we report the preparation of interconnected Fe-N/C nanofiber networks (Fe-N/C NNs) with low electrical resistance via electrospinning followed by maturing and pyrolysis. The Fe-N/C NNs show excellent ORR activity with onset and half-wave potential of 55 and 108 mV less than those of Pt/C catalyst in 0.5 M H2SO4. Intriguingly, the resulting Fe-N/C NNs exhibit 34% higher peak current density and superior durability than generic Fe-N/C ones with similar microstructure and chemical compositions. Additionally, it also displays much better durability and methanol tolerance than Pt/C catalyst. The higher electroactivity is mainly due to the more effective electron transport between the interconnected nanofibers. Thus, our findings provide a novel insight into the design of functional electrospun nanofibers for the application in energy storage and conversion fields.

No MeSH data available.


Related in: MedlinePlus