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 H2 molecules can bind to a Ca atom with a binding energy of ~0.2 eV/H2. A Ca-decorated zigzag graphene nanoribbon (ZGNR) can reach the gravimetric capacity of ~5 wt % hydrogen. We also consider various edge geometries of the graphene for Ca dispersion.
@article{arxiv.1002.1677,
title = {Calcium-Decorated Graphene-Based Nanostructures for Hydrogen Storage},
author = {Hoonkyung Lee and Jisoon Ihm and Marvin L. Cohen and Steven G. Louie},
journal= {arXiv preprint arXiv:1002.1677},
year = {2010}
}
Comments
15 pages, 4 figures. Accepted for publication in Nano Letters