In situ synthesis of graphene/carbon nanotube modified ordered mesoporous carbon as protective film of stainless steel bipolar plates for proton exchange membrane fuel cells

Either graphene or carbon nanotube (CNT) is in situ introduced in ordered mesoporous carbon film via a spin-coating method, followed by evaporation-induced self-assembly of precursors and post calcinations. Graphene-modified and CNT-modified ordered mesoporous carbon films show improved electronic conductivity of 0.35 and 0.41 S m^-1, and contact angles of 90° and 96°, respectively, which are significantly higher than the values of 0.0043 S m^-1 and 71° measured for the non-doped carbon film, suggesting enhanced graphitization degree and hydrophobic properties. Two different hybrid carbon films deposited on 304 stainless steels as bipolar plates for proton exchange membrane fuel cells reveal remarkable corrosion resistance, which show very low corrosion current densities of 0.140 μA cm^-2 and 0.008 μA cm^-2, in comparison with the 0.464 μA cm^-2 measured on the bare 304 stainless steel. Such hybrid carbon films with preserved ordered mesporous structure and satisfactory electrochemical performance on 304 stainless steels can be considered as promising candidates for bipolar plate materials in proton exchange membrane fuel cells.