Room temperature water splitting at the basal plane of graphene grown on nickel
In this joint experimental and theoretical Density Functional Theory (DFT) study we demonstrate that coupling of graphene (GR) with a Ni metal substrate can reduce the chemical neutrality of GR and induce some reactivity, sufficient to achieve water dissociation at room temperature.
We have used DFT calculations to evaluate the energetics of the dissociation reactions of single water molecules in different interface configurations. We find that water molecules can dissociate on GR without the need to intercalate below it to get into direct contact with the Ni substrate, being helped by Ni atoms trapped in the carbon vacancies during graphene growth. These Ni atoms are therefore identified as catalysts capable of locally initiating the dissociation of water molecules observed experimentally, which however eventually proceeds thanks to collective effects.
This strategy could be an opportunity to exploit the potential of graphene for hydrogen production and storage.
Authors: Monica Pozzo; Paolo Lacovig; Marco Bianchi; Monika Schied; Luca Bignardi; Francesca Zarotti; Roberto Felici; Dario Alfe; Silvano Lizzit; Rosanna Larciprete