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.
Highlights
Non-precious metal catalysts (NPMCs) for oxygen reduction reaction (ORR), which are more abundant, less expensive and more durable than the state-of-the-art Pt-based catalysts, have demonstrated significantly high activity and enormous potential in the commercialization of proton-exchange membrane fuel cells (PEMFCs)[1,2,3,4,5]
We report the synthesis of 3D interconnected Fe-N/C nanofiber networks (Fe-N/C NNs) by a novel method
On the basis of the electrochemical measurements, we found that Fe-N/C NNs displayed a higher diffusion current density, more positive half-wave potential, better stability and greater electron-transfer number than traditional electrospun Fe-N/C nanofiber mats (Fe-N/C NMs) in acidic media
Summary
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. The corresponding n value for Fe-N/C NNs is calculated to be around 4 over the potential range from 0.35 to 0.55 V (Fig. 5c), representing an efficient four-electron (4e−) dominated ORR process similar to Pt/C catalyst. The superior ORR activity of Fe-N/C NNs could be mainly attributed to the interconnected nanofiber networks which boosted the mass transport and electron transfer. The synergistic effect between nitrogen-doped Fe/C complex and high specific area for Fe-N/C NNs play important roles in the excellent ORR activity, superior durability and methanol tolerance. We believe that our method highlights the possibility for the fabrication of other interconnected nanofibers for battery, supercapacitor and fuel cells applications
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
