Effect of Ni atomic fraction on active species of graphene growth on Cu–Ni alloy catalysts: a density functional theory study

. In contrast, in a Cu-Ni catalyst with a high Ni atomic fraction, the C monomer species on the subsurface has high stability and acts as an active species that controls the cooling-induced segregation growth mechanism. This study provides an essential insight into the atomistic mechanism of graphene growth in Cu-Ni alloy catalysts.