Hydrogen adsorption on the α-graphyne using ab initio calculations

• A DFT study of the electronic and magnetic properties of α-graphyne is presented.
• Our results show the tuning of the magnetization by Hydrogenation.
• In the presence of Hydrogen atoms a relatively large band gap is opened in the electronic structure.

In this study, we use the Siesta ab initio code based on Density Functional Theory (DFT) to determine the feasibility of hydrogen storage on the α-graphyne. We examined the effect of hydrogen adsorption on the structural properties, the density of states of this nano structure. Calculations were performed in the GGA and LDA approximations. We find that in the case of chemical adsorption of hydrogen, functional exchange–correlation PBE (GGA) in explaining chemical bonds have more accuracy and leads to more stable structures. Adsorption is chemical and the binding energy of single and double hydrogen adsorption is −2.28 eV and −3.48 eV, respectively. Our calculations show that the adsorption of one hydrogen atom induces a magnetic moment as 1 μB, because of breaking of π-bonds and generate unpaired electron and system find ferromagnetic configuration. Further analysis indicates that adsorption of second hydrogen eliminates magnetization and the semi metalic α-graphyne structure attains a band gap of 2 eV upon hydrogenation.

We study the tuning of magnetization in the α-graphyne nano layer in the presence of hydrogen atoms.Figure optionsDownload as PowerPoint slide