Novel As-doped, As and N-codoped carbon nanotubes as highly active and durable electrocatalysts for O2 reduction in alkaline medium

•Novel arsenic-doped, arsenic and nitrogen-codoped CNTs are designed.•As doping improves the activity of CNTs or N-CNTs for oxygen reduction reaction.•Activities of CNTs or N-CNTs increase and then decrease with the As content increase.•DFT calculations indicate the As doping changes the electronic structure of CNTs.

To develop more efficient metal-free cathode electrocatalysts for fuel cells, novel arsenic (As)-doped, As and N-codoped carbon nanotubes are synthesized by chemical vapor deposition in this work. The as-prepared As-containing carbon nanotubes exhibit significantly enhanced activity and long-term durability for the oxygen reduction reaction (ORR) in alkaline medium, indicating that the doping of As or codoping As with other heteroatoms into carbon matrix could improve the ORR activity of carbon materials due to the changes in electronic and physical properties of carbon nanotubes evidenced by density functional theory calculations. Moreover, As-containing carbon nanotubes also display much better methanol tolerance, showing a good potential application for future fuel cells.

Graphical abstractNovel arsenic-doped, arsenic and nitrogen-co-doped carbon nanotubes are synthesized by chemical vapor deposition. Electrochemical test results indicate the synthesized arsenic-doped and arsenic and nitrogen-codoped carbon nanotubes all exhibit superior activities and long-term durability for the oxygen reduction reaction in alkaline medium.Figure optionsDownload full-size imageDownload as PowerPoint slide