| 초록 |
Metal-free catalysts based on graphene-carbon composite as fuel cell cathode catalysts have been studied to replace metal based catalysts. These catalysts were generally a mixture of graphene and carbon particles. As far as we know, composition of ultrathin carbon and graphene has not yet to be reported. Here we show ultrathin carbon coated on the graphene nanocomposite for ORR catalyst. The nanocomposite was synthesized by mixing with an polyurea networks sol and a graphene oxides solution, followed by thermal treatment. A nanoparticulate polyurea networks covalently attach to the graphene surface while mixing. It turned to ultrathin carbon by thermal treatment. The nanocomposite has high oxygen adsorption amount, high electrical conductivity, and high surface area. The resultant nanocomposite shows higher current density and onset potential than other metal-free catalyst. Especially, it shows superior current density and stability in alkaline solution compared to Pt/C catalyst. |
