External electric field: An effective way to prevent aggregation of Mg atoms on γ-graphyne for high hydrogen storage capacity

In this article, we investigate the hydrogen storage capacity of Mg-decorated γ-graphyne (Mg-G) based on DFT calculations. Our results indicate that an external electric field can effectively prevent Mg atoms aggregating on γ-graphyne sheet. The Mg-G, after electric field (F = 0.05 V/nm) treatment, can store up to ten H2 molecules and the hydrogen storage capacity is 10.64 wt%, with the average adsorption energy of 0.28 eV/H2. Our calculations demonstrate that Mg-G is a potential material for hydrogen storage with high capacity and might motivate active experimental efforts in designing hydrogen storage media.