Efficient hydrogen storage in boron doped graphene decorated by transition metals - A first-principles study

The hydrogen storage capacity of transition metal (TM) decorated boron (B) doped graphene surface through spill over mechanism have been studied using first principle calculations. Here we propose a new strategy to increase the hydrogen storage in the B-doped graphene surface. We decorated the surface with different TM atoms with different binding energy strengths in order to enrich both adsorption as well as desorption of hydrogen at ambient conditions. We find that among the considered TM atoms, the Ni, Pd and Co atoms are suitable for decorating B-doped graphene surface, which can be adsorbed stably on the surface. Our results show that the activation energies for H atom diffusion are much smaller than the previously reported values, indicating that a fast H diffusion on this proposed surface can be achieved. Further, the desorption energy of hydrogen on the Co is between 0.49 and 1.3 eV/molecule, which is close to the energies required to obtain reversible storage at room temperature.