Electrocatalytic activity of nitrogen plasma treated vertically aligned carbon nanotube carpets towards oxygen reduction reaction

We developed a simple and rapid procedure to prepare nitrogen-doped vertically aligned carbon nanotube carpets (VA-NCNTs). The VA-NCNTs were obtained by nitrogen plasma treatment of the vertically aligned multi-walled carbon nanotube carpets (VA-CNTs) directly grown on stainless steel substrates by chemical vapor deposition. This novel electrochemical interface reduces oxygen in lower overpotential under basic condition (onset potential at - 0.12 V vs. Ag/AgCl at pH 13) compared to untreated VA-CNTs (onset potential at - 0.22 V vs. Ag/AgCl at pH 13). The robustness of these nanostructures and ease of fabrication make VA-NCNTs promising non-platinum oxygen reduction catalysts that could be employed as cathode catalysts in real-time operation of alkaline fuel cell systems.