Horizontally Stacked Pristine and Li-doped C12 Carbyne Ring as Hydrogen Storage Materials: a DFT Study

Extensive research has been conducted on various materials, including two-dimensional systems, for their potential use in hydrogen storage. In this study, we examined a new material based on horizontally stacked carbyne rings (HSCR) decorated with lithium atom using density functional theory. Results have shown that HSCR is dynamically stable material shown by phonon dispersion and it is more energetically stable than isolated carbyne rings. It can be doped with lithium without energy barrier, and it achieves a 6.95 % hydrogen gravimetric capacity exceeding the 5.5% target of the US Department of Energy. Hydrogen molecules are adsorbed by physisorption through van der Waals interaction as shown by the charge density difference plots and calculated adsorption energy. With this new material, light-weight hydrogen storage materials towards green technology of renewable energy can be achieved using this carbon-based material.