The Role of Oxygen Functionalities for Enhanced Oxygen Reduction Activity in Carbon Nanotubes

摘要

The role of functional groups for the enhanced oxygen reduction activity in the multiwalled carbon nanotubes (MWNT) was investigated on defective MWNTs (DMWNTs). DMWNTs were prepared by chemically drilling the MWNT to modify the structure and content of functional groups on MWNT. Following cyclic voltammetry studies between the as prepared and after Ar annealed DMWNT, it is shown that even with very few quinone-functionalities present, the pre-wave (first 2e~- reduction), which is believed to be quinone-mediated ORR is still remained. This result suggests that the exact mechanism on the ORR in alkaline media still not well understood. The actual content of quinone functionalities together with the presence of defects may be the key for ORR activity in alkaline media.