Density functional theory (DFT) and time dependent density functional theory (TDDFT) calculations were performed to represent carbon dots surfaces. The addition of different oxygen functional groups to the aromatic carbon core structure and the stability in the interaction with silver nanoparticles was also investigated. Adsorption energies were evaluated in order to compare the competition for adsorption sites on silver surface with D-glucose and D-gluconate ion molecules. The -COOH and -COO groups and the interaction of the latter with silver were proposed to explain some features of the UV-visible absorption spectra, which could also contribute to an explanation for the charge observed on carbon dot surfaces.

Rh adatom stability on graphene, with and without defects has been investigated by density functional theory (DFT). The feasibility to achieve uniform dispersion for the metallic atom and the hydrogen storage capacity for each system were evaluated.