Computational Investigation of MgH2/Graphene Heterojunctions for Hydrogen Storage

Safe and effective storage of hydrogen fuel is a step toward a hydrogen economy. As a model storage media, magnesium hydride (MgH2) experiences sluggish dehydrogenation dynamics, although its storage capacity is excellent. This computational work investigated MgH2/graphene heterojunction, focusing on the effect of graphene dopants on hydrogen release from MgH2. It is demonstrated that dopants in graphene can improve MgH2 dehydrogenation, reducing both reaction barrier and reaction energy. It is further predicted that excellent dehydrogenation thermodynamics and kinetics can be obtained with the use of B/P codoped graphene (BP@graphene). Given that graphene codoping has been experimentally studied for years, the proposed MgH2/BP@graphene heterojunction is approachable and recommended for experimental validation.