Graphene on nickel (100) micrograins: Modulating the interface interaction by extended moiré superstructures

Interaction with the substrate strongly affects the electronic/chemical properties of supported graphene. So far, graphene grown by chemical vapor deposition (CVD) on catalytic single crystal transition metal surfaces - mostly 3-fold close-packed - has mainly been studied. Herein, we investigated CVD graphene on a polycrystalline nickel (Ni) substrate, focusing in particular on (100) micrograins and comparing the observed behavior with that on single crystal Ni(100) substrate. The symmetry-mismatch leads to moiré superstructures with stripe-like or rhombic-network morphology, which were characterized by atomically-resolved scanning tunneling microscopy (STM). Density functional theory (DFT) simulations shed light on spatial corrugation and interfacial interactions: depending on the misorientation angle, graphene is either alternately physi- and chemisorbed or uniformly chemisorbed, the interaction being modulated by the (sub)nanometer-sized moiré superstructures. Ni(100) micrograins appear to be a promising substrate to finely tailor the electronic properties of graphene at the nanoscale, with relevant perspective applications in electronics and catalysis.Fil: Zou, Zhiyu. The Abdus Salam. International Centre for Theoretical Physics; ItaliaFil: Carnevali, Virginia. Università degli Studi di Trieste; ItaliaFil: Jugovac, Matteo. Università degli Studi di Trieste; Italia. Helmholtz Gemeinschaft. Forschungszentrum Jülich; Alemania. The Abdus Salam. International Centre for Theoretical Physics; ItaliaFil: Patera, Laerte L.. Helmholtz Gemeinschaft. Forschungszentrum Jülich; Alemania. Vienna University of Technology; AustriaFil: Sala, Alessandro. Università degli Studi di Trieste; ItaliaFil: Panighel, Mirco. Helmholtz Gemeinschaft. Forschungszentrum Jülich; Alemania. Università degli Studi di Trieste; ItaliaFil: Cepek, Cinzia. Università degli Studi di Trieste; ItaliaFil: Soldano, Germán. Helmholtz Gemeinschaft. Forschungszentrum Jülich; AlemaniaFil: Mariscal, Marcelo. Università degli Studi di Trieste; ItaliaFil: Peressi, Maria. Universitat Regensburg; AlemaniaFil: Comelli, Giovanni. Laboratorio Nazionale Tasc;Fil: Africh, Cristina. Università degli Studi di Trieste; Itali