Theoretical investigation of ede-decorated zigzag graphene nanoribbons by scandium with lithium: A potential hydrogen storage material

With the recent rise in graphene's popularity and the difficulty in finding an appropriate storage for molecular hydrogen, the hydrogen storage capability of graphene nanoribbon was investigated. It was found that through doping, GNR's chemical and electronic properties can be manipulated and heightened depending on the dopants used. Moreover, modifying and decorating GNR edges also increased the hydrogen storage capability of GNRs. For this study, the combination of Lithium and Scandium atoms were investigated pertaining to the amount of hydrogen molecules it can adsorbed in a Zigzag GNR system. Under the basis of quantum chemical calculations, doping lithium into an edge-modified ZGNR by scandium over enhances its H2 storage capacity. The number of H2 molecules adsorbed by Scandium and Lithium individually, are 5 and 4, H2 molecules respectively. The number of Lithium doped is proportional to the amount of H2 molecules adsorbed therefore increasing its storage capability. The highest weight percentage of H2 achieved in this research is 6.0832% from the 6Li-10-ZGNR>Sc/2 system which is above the DOE target of 5.5%. Moreover, the maximum number of H2 molecules that can be stored in that system is 54 H2 molecules with an average binding energy of -10.52 eV.