Enhanced hydrogen storage kinetics in Mg@FLG composite synthesized by plasma assisted milling

摘要

Mg-based materials as potential hydrogen storage candidates, however, are suffering from sluggish kinetics during absorption and desorption processes. Here in this work, embedding Mg particles on few-layer graphene nanosheets (FLG) via dielectric barrier discharge plasma (DBDP) assisted milling was synthesized to improve hydrogen storage properties of Mg particles. The SEM observation demonstrates that Mg particles are distributed uniformly on the surface of the graphite layer in the Mg@FLG composite. The obtained Mg based composite (Mg@FLG) shows a hydrogen storage capacity of similar to 5 wt%. From the isothermal dehydrogenation kinetic curves, the composite could desorb similar to 4.5 wt% hydrogen within 25 min at 300 degrees C. Compared with pure Mg, the dehydriding kinetics of the hydrogenated Mg@FLG composite is significantly elevated, showing an activation energy of 155 J/(mol.K). In addition, the dehydrogenation peak temperature of the Mg@FLG decreases dramatically from 431 to 329 degrees C for MgH2. This work implies a promising composite formation technique in Mg-based materials to enhance hydrogen storage kinetics. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.