▎ 摘　　要

DFT calculations have been performed to explore the aminotriazine adsorption on graphene surfaces. Relative energies, equilibrium geometries and electronic structures of monomer and dimer of aminotriazine molecules adsorbed at the surface were investigated and analyzed in details. It was found that the hydrogen atoms in the NH(2) group of aminotriazine molecules are directed toward the graphene surface, and the adsorption energy increases as the NH(2) group is added. The adsorbed aminotriazine molecules facilely form a dimer through the hydrogen bonding interactions, and the two aromatic rings of optimized structure of 2-amino-1,3,5-triazine (B) dimmer (denoted by B(2)) and melamine (D) dimmer (denoted by D(2)) are parallel to the graphene sheet. The large deviation of the averaged adsorption energy of B(2) and D(2) compared to monor adsorption may reflect the increase of pi-pi repulsion and the effect of hydrogen bond formation. The electronic structure analyses reveal that the formation of hydrogen bonds in melamine dimer has great influence on the adsorption mode at the graphene surface.