Novel phosphorus-doped multiwalled nanotubes with high electrocatalytic activity for O2 reduction in alkaline medium

Phosphorus-doped multiwalled carbon nanotubes (MCNTs) were synthesized by the thermolysis and characterized by electron microscopy and microanalysis technique and evaluated with electrochemical methods. The results revealed that carbon nanotube length became shorter, the tube diameters increased and the yield of MCNTs reduced gradually with the increase of the concentration of triphenylphosphine in toluene solution, and the tube diameters increased with the increase of the synthesis temperature. Moreover, the phosphorus doping significantly improved the electrocatalytic activity of carbon nanotubes for the oxygen-reduction reaction in alkaline media, and the carbon nanotubes doped with small amounts of phosphorus exhibited higher electrocatalytic activity and stability than Pt/C catalyst.

Graphical abstractP-doped MCNTs synthesized by thermolysis of toluene solution containing ferrocene and TPP, showed much higher electrocatalytic activity (3, 3′) for ORR in alkaline electrolyte solution than Pt–C/GC (1, 1′) and MCNTs (2, 2′) before (solid curves) and after (dotted curves) continuous potential cycling sweep for 5 days.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Phosphorus-doped multiwalled carbon nanotubes (P-MCNTs) are prepared by thermolysis. ► Phosphorus doping significantly improves the oxygen-reduction activity of MCNTs. ► P-MCNTs exhibit higher electrocatalytic activity and stability than Pt/C catalyst.