Journal of Materials Science, Vol.54, No.17, 11618-11634, 2019
Electrocatalysts for oxygen reduction reaction based on electrospun polyacrylonitrile, styrene-acrylonitrile copolymer and carbon nanotube composite fibres
In this work, polyacrylonitrile (PAN), styrene-acrylonitrile copolymer (SAN) and multi-walled carbon nanotubes (MWCNTs) composite fibres (PAN/SAN/CNT) were prepared by electrospinning. The electrospun fibres were further pyrolysed (800-1200 degrees C) in N-2 atmosphere with or without prior stabilisation (at 250 degrees C) in air to produce electrocatalyst materials for oxygen reduction reaction (ORR). The ORR was studied in alkaline solution by linear sweep voltammetry and rotating disc electrode (RDE) method. Scanning electron microscopy images revealed the tubular structure of the pyrolysed PAN/SAN/CNT fibres with visible MWCNTs. According to the X-ray photoelectron spectroscopy results, the prepared catalysts consisted of carbon, oxygen and nitrogen. According to the RDE results, the most active catalyst towards the ORR (the onset and half-wave potential of -0.13V and -0.29V vs SCE in 0.1M KOH, respectively) was obtained by pyrolysing non-stabilised PAN/SAN/CNT fibres at 1100 degrees C. The ORR activity of the best performing catalyst is attributed to the nitrogen species, quinone groups and porous tubular structure of the catalyst material.