Modeling graphene oxide nanoribbons: A first-principles study

In this study, we modeled a graphene oxide nanoribbon (GONR) using first-principles calculations based on Density Functional Theory. The construction of the GONR involved examining the interactions of the oxygen functional groups (OFGs) -O-, -OH, -CO, and -COOH with the graphene nanoribbon (GNR), as well as their interactions with one another through direct contact or mediated by the GNR. To understand the changes experienced by the system when adsorbing different OFGs, we analyzed structural modifications and electronic properties by exploring the band structure, HOMO and LUMO frontier orbitals, and the resulting magnetization. We found that the adsorption of these OFGs occurs preferentially at the edges and near other groups. The concentration of OFGs at each edge affects the electronic properties, which are reflected in the active sites defined by the isosurfaces of the frontier orbitals. The creation of a monovacancy in the final configuration of the GONR leads to a shift in the electronic bands around the Fermi level. These changes enhance the density and distribution of active sites, which are primarily dominated by the vacancy but also present throughout the nanoribbon. These results suggest its potential application in studying $\pi$-$\pi$ interactions when adsorbing organic molecules.