Density functional calculation of transition metal adatom adsorption on graphene

The adsorption of 15 different transition metal adatoms on graphene is studied using first-principles density-functional theory with the generalized gradient approximation. The adsorption energy, stable geometry, density of state, and magnetic moment of each adatom-graphene system are calculated. For the adatoms studied from Sc to Zn of the Periodic Table, and noble metals, the distortion of the graphene layer on B of T sites is quite significant in some cases, and the adsorption is characterized by strong hybridization between adatom and graphene electronic states. The favored adsorption site indicates the main chemical bond between adsorbate and graphene. Half filled d shell TM atoms and Au, Ag, Zn have small adsorption energy. The reduction in magnetic moment from the isolated to the adsorbed atom is explained by the perspective of charge transfer, and electron shift between different orbit states of the adatom.