▎ 摘　　要

Hydrogen storage properties of Li-decorated graphene oxides containing epoxy and hydroxyl groups are studied by using density functional theory. The Li atoms form Li4O/Li3OH clusters and are anchored strongly on the graphene surface with binding energies of -3.20 and -2.84 eV. The clusters transfer electrons to the graphene substrate, and the Li atoms exist as Li+ cations with strong adsorption ability for H-2 molecules. Each Li atom can adsorb at least 2H(2) molecules with adsorption energies greater than -0.20 eV/H-2. The hydrogen storage properties of Li-decorated graphene at different oxidation degrees are studied. The computations show that the adsorption energy of H-2 is -0.22 eV/H-2 and the hydrogen storage capacity is 6.04 wt% at the oxidation ratio O/C =1/16. When the O/C ratio is 1:8, the storage capacity reaches 10.26 wt% and the adsorption energy is -0.15 eV/H-2. These results suggest that reversible hydrogen storage with high recycling capacities at ambient temperature can be realized through light-metal decoration on reduced graphene oxides. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.