Preparation of nitrogen-doped carbon submicrotubes by coaxial electrospinning and their electrocatalytic activity for oxygen reduction reaction in acid media

Nitrogen-doped carbon tubes (NCTs) with submicron diameters were synthesized by coaxial electrospinning and subsequent heat treatment in NH3 or N2 atmosphere. Polyacrylonitrile (PAN) and polyvinylidenedifluoride (PDVF) mixture solutions were used as the outer fluids during coaxial electrospinning, and after heat treatment PAN converted into nitrogen-doped carbon species, while PVDF decomposed and left some pores in the tube walls. In comparison with the NCTs treated in N2, the NH3-etched NCTs had a smaller diameter of about 350 nm and showed much better electrocatalytic activity for oxygen reduction reaction (ORR) in acid media.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► N-doped carbon submicrotubes were prepared by coaxial electrospinning. ► NH3-etched NCTs had smaller diameter and more exposed edge planes. ► NH3-etched NCTs had better ORR activity than N2-treated NCTs.