Transition-metal-doping-enhanced hydrogen storage in boron nitride systems

The authors perform spin-polarized density functional theory simulations on the 3d transition metal (TM) series (Sc to Fe) doped system borazine (B3N3H6). The Sc and Ti bind most strongly to borazine but Cr and Mn do not bind at all. With increasing hydrogen content the bound hydrogen species becomes molecular. The maximum amount of hydrogen that can be stored is 4H(2) per TM atom for Sc, Ti, and V dopants (similar to 6 wt % bound hydrogen). The binding energy of hydrogen in these systems is of the order of -0.3 to -0.7 eV/H-2, desirable for practical hydrogen storage applications. The optimum dopant is titanium. (c) 2006 American Institute of Physics.