Department of Physics, Henan Normal University, Xinxiang, Henan 453007, People's Republic of China.
J Phys Condens Matter. 2010 Aug 11;22(31):316005. doi: 10.1088/0953-8984/22/31/316005. Epub 2010 Jul 16.
First-principles total energy calculations are performed to investigate the formation and structures of Pt clusters on graphene. It is found that the formation energy of Pt on graphene increases with increasing Pt coverage. The structures of the absorbed Pt are that it is at the bridge site for a single Pt atom absorption, but form a dimerized cluster when two atoms are absorbed on graphene. For three- and four-Pt-atom absorption, linear and tetrahedral structures form, respectively, and the three-dimensional tetrahedral Pt(4) cluster is most stable in all the configurations investigated. There is a strong interatomic interaction among Pt atoms and so they tend to form clusters. While no magnetic behavior is expected after a single Pt atom is absorbed on graphene, the absorption of tetrahedral Pt(4) leads to Fermi level shifting to the valence band and the spin waves of C atoms in graphene become asymmetric and so they exhibit magnetism. The magnetic properties can thus be tuned by Pt absorption on graphene. The ultimate aim is to apply it in catalytic activity and electronic devices.
采用第一性原理的全能量计算方法，研究了 Pt 团簇在石墨烯上的形成和结构。结果表明，Pt 在石墨烯上的形成能随着 Pt 覆盖率的增加而增加。吸附 Pt 的结构为：当单个 Pt 原子吸附时，处于桥位，而当两个原子吸附在石墨烯上时，形成二聚体团簇。对于三原子和四原子的吸附，分别形成线性和四面体结构，而在所有研究的构型中，三维四面体 Pt(4)团簇最稳定。Pt 原子之间存在很强的原子间相互作用，因此它们倾向于形成团簇。虽然单个 Pt 原子吸附在石墨烯上后不会表现出磁行为，但四面体 Pt(4)的吸附会导致费米能级移至价带，使石墨烯中 C 原子的自旋波变得不对称，从而表现出磁性。因此，Pt 在石墨烯上的吸附可以调节其磁性。最终目标是将其应用于催化活性和电子器件中。
