▎ 摘 要
Cobalt/ nitrogen co-doped carbon nanotube/graphene composites (Co/N-CNT/Gr-X, X represents the calcination temperature) were prepared by high temperature nitrogen doping with homemade graphene/N-methylpyrrolidone (NMP) dispersion and Co (NO3)(2) as precursors. The results show that the solvent NMP in the graphene dispersion as a carbon source forms high. density carbon nanotubes on the surface of graphene with cobalt salt as catalysts, which provided a three. dimensional porous structure favorable for massive transfer of electrolyte ions. In addition, some cobalt ions were oxidized to form cobalt oxide and the others reacted with N to form a Co-N active site, thus leading to a markedly enhanced oxygen reduction reaction (ORR) performance. Among them, Co/N-CNT/Gr. 800 exhibits a good performance in electrocatalytic activity, stability, and immunity towards methanol comparing with commercial carbon platinum (Pt/C) catalyst, the reduction potential and limiting current density of which were -0.137 V (vs. SCE) and 4.24 mA/cm(2), respectively. And the electron transfer number was 3.34.