Hydrogen storage in Ni–B nanoalloy-doped 2D graphene

Two-dimensional graphene material is doped with Ni–B nanoalloys via a chemical reduction method, and shows that the optimal graphene doped with Ni (0.14 wt.%) and B (0.63 wt.%) has a hydrogen capacity of 2.81 wt.% at 77 K and 106 kPa, which is more than twice of that of the pristine graphene. The measured adsorption isotherms of hydrogen and nitrogen suggest that the Ni–B nanoalloys function as catalytic centers to induce the dissociative adsorption of hydrogen (spillover) on the graphene. The Ni–B nanoalloys without using any noble metal may be a promising catalyst for hydrogen storage application.

► A Ni–B nanoalloy–doped 2D graphene has a higher hydrogen capacity than graphene.
► Ni–B alloys function as catalytic centers to induce dissociation of the adsorbed H.
► Noble metal–free Ni–B nanoalloys show better catalytic activity.