Mg@C60 nano-lamellae and its 12.50 wt% hydrogen storage capacity

Abstract The design and synthesis of new hydrogen storage materials with high capacity are the prerequisite for extensive hydrogen energy application which can be achieved by multi-site hydrogen storage. Herein, a Mg@C 60 nano-lamellae structure with multiple hydrogen storage sites has been prepared through a simple ball-milling process in which Mg nanoparticles (∼5 nm) are homogeneously dispersed on C 60 nano-lamellae. The as-obtained C 60 /Mg nano-lamellae displays an excess hydrogen uptake of 12.50 wt% at 45 bar, which is far higher than the theoretical value (7.60 wt%) of metal Mg and the US Department of Energy (DOE) target (5.50 wt%, 2020 year), also the experimental values reported by now. The enhanced hydrogen storage mainly comes from several storage sites: MgH 2 , H x –C 60 (C H chemical bonding), H 2 @C 60 (the endohedral H 2 in C 60 ). Interestingly, the hybridization of Mg and C 60 not only facilitate the dissociation of H 2 molecules to form C H bonding with C 60 , but also promote the deformation of C 60 and access H 2 molecules into the cavity of C 60 . This work provides new insight into the underlying chemistry behind the high hydrogen storage capacities of a new class of hydrogen storage materials, fullerene/alkaline-earth metals nanocomposites.