Interaction of Transition Metals with Carbon Nanostructures

Recent theoretical studies have shown that transition-metal (TM) decorated carbon nanotubes and fullerenes may serve as promising media for hydrogen storage. However, one prerequisite for this functionality is that the metal atoms decorate the carbon nanostructures as a homogeneous layer. To date, no experimental evidence supports this feasibility; instead, several subsequent studies indicated strong preference of clustering by the TM atoms. In this talk, we investigate several possible ways to prevent TM clustering on the surfaces of carbon nanostructures, based on first-principles total energy calculations. First, we discuss the energetics and kinetics of various TMs as they interact with carbon nanostructures. We then explore the possibility to suppress or enhance clustering by electron or chemical doping.