Carbon nanofiber growth on thin rhodium layers

A thin layer of carbon nanofibers (CNFs) was synthesized on a thin polycrystalline rhodium (Rh) metal layer by decomposing ethylene in the presence of hydrogen. Interaction of Rh crystals with carbon results in fragmentation and formation of Rh-nanoparticles, facilitating CNF growth. CNFs are immobilized on the surface by an apparently amorphous intermediate layer containing both Rh and C. Maximum CNF growth was achieved at intermediate hydrogen concentrations. A CNF growth mechanism by (sub-) surface diffusion of carbon on Rh is suggested.