title: Calcium-decorated graphene-based nanostructures for hydrogen storage.
abstract: We report a first-principles study of hydrogen storage media consisting of calcium atoms and graphene-based nanostructures. We find that Ca atoms prefer to be individually adsorbed on the zigzag edge of graphene with a Ca-Ca distance of 10 A without clustering of the Ca atoms, and up to six H(2) molecules can bind to a Ca atom with a binding energy of approximately 0.2 eV/H(2). A Ca-decorated zigzag graphene nanoribbon (ZGNR) can reach the gravimetric capacity of approximately 5 wt % hydrogen. We also consider various edge geometries of the graphene for Ca dispersion.
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: Hoonkyung
authors.initials: H
authors.lastname: Lee
authors.forename: Jisoon
authors.initials: J
authors.lastname: Ihm
authors.forename: Marvin L
authors.initials: ML
authors.lastname: Cohen
authors.forename: Steven G
authors.initials: SG
authors.lastname: Louie
mesh_terms: D002118:Calcium / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D006108:Graphite / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry* / Q000302:isolation & purification*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006108:Graphite; D006859:Hydrogen; D002118:Calcium