Electrospun bamboo-like Fe3C encapsulated Fe-Si-N co-doped nanofibers for efficient oxygen reduction.

In this work, a novel catalyst of oxygen reduction reaction (ORR) was designed and fabricated by electrospinning, photo-curing and carbonization, based on polymer poly(dimethylsilylene ethynylenephenyleneethynylene) (PMSEPE) and metal organic frameworks (MOFs)-Materiaux de l'Institute Lavosier-101(Fe) (MIL-101(Fe)). The optimal catalyst PMSEPE/MIL-101(Fe)-800, which was carbonized at 800 °C, presented a bamboo-like nanofiber structure with a high degree of graphitization, a high specific surface area (302.3 m2/g) and a high yield (64.17%). Fe3C particles were found to be encapsulated into the Fe-Si-N co-doped carbon nanofibers. In the electrochemical tests, PMSEPE/MIL-101(Fe)-800 showed an onset potential of 0.935 V (vs. RHE) and a diffusion limit current of 6.01 mA/cm2 (vs. RHE) in 0.1 M KOH aqueous solution, of which performances are competitive to commercial 20 wt% Pt/C. PMSEPE/MIL-101(Fe)-800 also exhibited a higher methanol tolerance and duration stability. Further Zn-air battery test used by PMSEPE/MIL-101(Fe)-800 suggested its potential for the application of fuel cell.