The Effect of the Oxygen-Containing Functional Groups on the Electrochemical Reduction of Oxygen of Multi-Walled Carbon Nanotubes in Acid Media

The effect for oxygen reduction characteristics of O-functionalities formed on the edge planelike defects at the open ends of multiwalled carbon nantoubes (MWCNTs) and on the hole defects at the tube walls was investigated by means of the rotating disk electrode method. The onset potential of the electrochemical reduction of oxygen for MWCNTs shifts to the positive direction of 0.19V, while the O-functionalities were removed from the defect sites. This result suggests that the control of functional groups is important for the control of the oxygen reduction catalyst activity.