Carbon nanofiber growth on carbon paper for proton exchange membrane fuel cells

Homogeneous deposition precipitation (HDP) of nickel has been investigated for the growth of carbon nanofibers (CNFs) on carbon paper for use in proton exchange membrane fuel cells as a gas diffusion layer. Selective CNF growth on only one side of carbon paper is required to transfer the generated protons on platinum catalyst fast enough to avoid any proton mass transfer losses. For this purpose, a mask deposition holder was designed to deposit the nickel hydroxide which is reduced to nickel with hydrogen before catalyzing the CNF growth. The deposition time effect on the catalyst loading and the effect of the catalyst loading variation on the yield of CNF growth on carbon paper were investigated. Both effects had linear dependence in the region of interest. The HDP of nickel on the carbon paper ensured strong attachment of nickel crystals on the carbon paper fibers keeping the porosity at a promising level with an acceptable BET area of CNFs. The HDP method provides fine-tuning in the CNF layer thickness only on one side of the carbon paper with good reproducibility in the deposition of nickel.