Abstract
Fe(3)O(4) nanoclusters anchored on porous reduced graphene oxide (Fe(3)O(4)@rGO) have been synthesized by a one-step hydrothermal route, and then ball milled with LiBH(4) to prepare a hydrogen storage composite with a low onset dehydrogenation temperature, and improved dehydrogenation kinetics and rehydrogenation reversibility. The LiBH(4)-20 wt% Fe(3)O(4)@rGO composite begins to release hydrogen at 74 °C, which is 250 °C lower than for ball-milled pure LiBH(4). Moreover, the composite can release 3.36 wt% hydrogen at 400 °C within 1000 s, which is 2.52 times as high as that of pure LiBH(4). Importantly, it can uptake 5.74 wt% hydrogen at 400 °C under 5 MPa H(2), and its hydrogen absorption capacity still reaches 3.73 wt% after 5 de/rehydrogenation cycles. The activation energy (E (a)) of the hydrogen desorption of the composite is decreased by 79.78 kJ mol(-1) when 20 wt% Fe(3)O(4)@rGO is introduced into LiBH(4) as a destabilizer and catalyst precursor, showing enhanced thermodynamic properties. It could be claimed that not only the destabilization of Fe(3)O(4), but also the active Li(3)BO(3) species formed in situ, as well as the wrapping effect of the graphene, synergistically improve the hydrogen storage properties of LiBH(4). This work provides insight into developing non-noble metals supported on functional graphene as additives to improve the hydrogen storage properties of LiBH(4).