Systematic Theoretical Study of Electronic Structures and Stability of Transition-Metal-Adsorbed Graphdiyne Clusters

Graphdiyne (GDY), a new two-dimensional carbon allotrope, has attracted much attention due to the unique structural features with sp- and sp(2)-hybridized carbon atoms. For the first time, we have systematically performed a theoretical investigation on the electronic structures and stabilities of the transition metal-adsorbed GDY (namely, TM@GDY (TM = Sc-Zn)) clusters by means of density functional theory calculations. Accordingly, the TM@GDY (TM = Sc-Mn) clusters with partially filled 3d orbitals have a distorted in-plane conjugated framework, whereas in Zn@GDY, there is a large distance between a fully filled orbital on the Zn atom and the GDY surface. The analysis of binding energy reveals that the TM@GDY (TM = Sc, Ti, V, Ni) clusters possess higher structural stabilities than others and that transition-metal atoms can modulate the electronic structures. Moreover, the natural charge always transfers from the metal to the GDY framework and the transferred charges strongly depend on the increasing atomic number, especially for the 4s orbital of the metal. On the basis of energy decomposition, it is found that the net contributions from Mn to Ni are relatively small, leading to the slightly strong binding energies. These predicted results will provide a fundamental reference for screening the model of atomic catalysts and further exploring the potential applications.