With the combination of experiment and first-principles theory, we have evaluated and explored the catalytic effects of graphitic nanofibres for hydrogen desorption behaviour in magnesium hydride. Helical form of graphene nanofibres (HGNF) have larger surface area, curved configuration and high density of graphene layers resulting in large quantity of exposed carbon sheet edges. Therefore they are found to considerably improve hydrogen desorption from MgH₂ at lower temperatures compared to graphene (onset desorption temperature of MgH₂ catalyzed by HGNF is 45 °C lower as compared to MgH₂ catalyzed by graphene). Using density functional theory, we find that graphene sheet edges, both the zigzag and armchair type, can weaken Mgsingle bondH bonds in magnesium hydride. When the MgH₂ is catalyzed with higher electronegative and reactive graphene edge of graphene, the electron transfer occurs from Mg to carbon, due to which MgH₂ is dissociated into hydrogen and Mgsingle bondH component. The Mg gets bonded with the graphene edge carbon atoms in the form of Csingle bondMgsingle bondH and Csingle bondH bonds. In the as formed Csingle bondMgsingle bondH, the graphene edges “grab” more electronic charge as compared to the normal charge donation of Mg to H. This leads to the weakening of the Mgsingle bondH bond, causing hydrogen to desorbs at lower temperatures.