Hydrogen storage in a Ni–B nanoalloy-doped three-dimensional graphene material

A three-dimensional graphene material was doped with Ni–B nanoalloys via a chemical reduction process. The graphene doped with Ni (0.83 wt%) and B (1.09 wt%) shows the best hydrogen storage capacity of 4.4 wt% at 77 K and 106 kPa, which is better than that of pristine graphene by three times, and is also excellent among all carbon-based materials. Analysis of hydrogen isotherms and isosteric heat of adsorption suggests that doping with an appropriate amount of Ni–B nanoalloys can result in the dissociative chemisorption of hydrogen molecules by spillover to achieve the high hydrogen storage capacity.