Density functional theory calculations of hydrogen adsorption on Ti-, Zn-, Zr-, Al-, and N-doped and intrinsic graphene sheets

The effect of different doped atoms on the interactions between graphene sheets and hydrogen molecules were investigated by density functional theory calculations. The interactions between graphene sheets and hydrogen molecules can be adjusted by doped atoms. The Ti-doped graphene sheet had the largest interaction energy with the hydrogen molecule (approximately -0.299 eV), followed by the Zn-doped graphene sheet (about -0.294 eV) and then the Al-doped graphene sheet (approximately -0.13 eV). The doped N atom did not improve the interactions between the N-doped graphene sheet and the hydrogen molecule. Our results may serve as a basis for the development of hydrogen storage materials.