High-capacity hydrogen storage in zirconium decorated psi-graphene: acumen from density functional theory and molecular dynamics simulations

Abstract

We have explored the hydrogen storage capacity of zirconium doped psi-graphene employing Density Functional Theory. The Zr atom binds strongly on psi-graphene with a binding energy of −3.54 eV due to charge transfer from Zr 4d orbital to C 2p orbital. Zr atom adsorbs 9H2 molecules with an average binding energy of −0.38eV/H2 and an average desorption temperature 484.21 K. The gravimetric weight percent is 11.3 which meets the benchmark set by DoE. Zr and H2 molecules bond by Kuba's interactions involving electron flow between metal d orbital and H 1s orbital. We have investigated the structural stability of the system at room temperature and at 400 K using ab-initio Molecular Dynamics (MD) simulations. Thus, we can attribute that our system is stable, recyclable and can be used as an excellent hydrogen storage medium. This work may inspire the experimentalist to synthesize psi-graphene based material for hydrogen storage.