Cooperative Effects of N-Doping and Ni(111) Substrate for Enhanced Chemical Reactivity of Graphene: The Case of CO and O2 Adsorption

While pristine graphene (G) is chemically inert, chemical doping is currently regarded as a leading strategy for fine-tuning both G electronic properties and reactivity toward adsorbed species. Following recent experimental work, we demonstrate that deposition of G on Ni(111) and introduction of N-based defects in the G lattice lead to cooperative effects, determining sizeable chemical reactivity toward CO adsorption. CO chemisorption is predicted on pyridinic-, pyrrolic-, and epoxy-like defects generated by N-ion bombardment, compatibly with the experiment. Comparison with O-2 adsorption further reveals selective reactivity of the defective system with respect to distinct gaseous moieties, thereby opening new pathways toward high-sensitivity CO sensors and controlled surface chemical reactions.