Hydrogen adsorption on decorated graphyne and its analogous with Na

Highlights: • Structural stability of Na decorated single- and double- sided graphyne and its analogous. • Hydrogen storage capacity of decorated graphyne and its analogous, based on Density Functional Theory (DFT) by PBEsol, vdW-DF2-B86R and vdW-DF2 approximations. • Electrical properties like density of states and band gap after Na decoration and hydrogen adsorption. - Abstract: In this paper, we have addressed the structural stability and hydrogen storage capability of single side and double side Na-decorated γ-Graphyne, Graphyne-like Boron Nitride and CCBN-yne, using three methods of density functional theory approximation: PBEsol, vdW-DF2-B86R and vdW-DF2. We also investigated the electronic properties of these structures, decorated by Na atoms and adsorbing hydrogen, such as density of states and band structure. Our results showed that hydrogen can be adsorbed up to three molecules per Na atom. We found the optimal geometries of adsorbed hydrogen molecules on adsorption candidates. We also found that Direct band-gap at "M" point changes after decoration and adsorption in mentioned structures. Finally, we explored metallic structures for hydrogen storage which can be used in the industry of fuel cells.