Modulated moiré superstructures of graphene on Ni(100): stability and reactivity

The interaction of graphene with the substrate strongly affects its electronic and chemical properties [1]. We focus in particular on graphene on Ni(100), where moiré superstructures with different modulation of the interface interaction are established, depending on the graphene/substrate misorientation angle. Stability, electronic and reactivity properties of
various moiré structures are studied combining surface science techniques (mainly scanning tunneling microscopy) and numerical simulations based on Density Functional Theory and Kinetic Monte Carlo approaches [2]. Stripe-like moiré structures offer alternate regions characterized by weak/strong graphene-surface bonding, constituting a unique environment for a chemistry "above the cover" and "under the cover" [3]. We discuss preliminary results of the interaction with small molecules of environmental importance. We found that carbide segregation at the interface upon temperature cooling may affect the graphene-surface interaction, causing for instance local detachment of the graphene overlayer in stripe-like moiré
structures.

[1] Bianchini F et al., 2014 J. Phys. Chem. Lett., 5 (3), 467-473
[2] Zhiyu Z, Carnevali V et al., to be published in Carbon.
[3] Fu Q, Bao X, 2017 Chem. Soc. Rev., 46, 1842-1874