Two-step implantation of gold into graphene

Abstract

As a one-atom thick, mechanically strong, and chemically stable material with unique electronic properties, graphene can serve as the basis for a large number of applications. One way to tailor its properties is the controlled introduction of covalently bound heteroatoms into the lattice. In this study, we demonstrate efficient implantation of individual gold atoms into graphene up to a concentration of 1.7×1011 atoms/cm2 via a two-step low-energy ion implantation technique that overcomes the limitation posed by momentum conservation on the mass of the implanted species. Atomic resolution scanning transmission electron microscopy imaging and electron energy-loss spectroscopy reveal gold atoms occupying double vacancy sites in the graphene lattice. The covalently bound gold atoms can sustain intense electron irradiation at 60 kV during the microscopy experiments. At best, only limited indication of plasmonic enhancement is observed. The method demonstrated here can be used to introduce a controlled concentration of gold atoms into graphene, and should also work for other heavier elements with similar electronic structure.

Identifying and manipulating single atoms with scanning transmission electron microscopy

“…This is not the case for germanium, which firstprinciples modeling revealed does not move sufficiently swiftly, 73 explaining why they could not be manipulated. The same issue very likely applies to other heavier elements such as platinum 56,74 and gold, 76 which have not been observed to move under irradiation. Further, the impurity ideally needs to be stable in a buckled three-coordinated configuration, which is not typically the case for many metals.…”

In Situ Observation of the Motion of Platinum and Gold Single Atoms on Graphene Using Aberration-Corrected Electron Microscopy

“…The single metal atoms supported on graphene can be directly observed with transmission electron microscopy (TEM). Several metal atoms have been observed via TEM at room temperature, such as the Au atom, − Cr atom, − Al atom, Fe atom, ,, Cu atom, , Si atom, ,, In atom, Ge atom, P atom, and Pt atom. ,,,,, These studies showed that each of these single metal atoms has been observed at the edges of the graphene carbon network (including with defects in the case of single-layer graphene).…”

“…Previous studies have suggested that single metal atoms are less likely to be present on graphene terraces 33,54 and that graphene edges and defects provide stable binding sites. 25,29,31 Additionally, because single metal atoms bonded to the graphene edge show a difference in the bonding energy between the metal and carbon depending on the location, 23 a single metal atom with a weaker bond is easily broken under electron beam irradiation at room temperature; thus, it moves to the next stable binding site. 31 In this study, there were no single metal atoms on monolayer graphene.…”

Heteroatom Codoped Graphene: The Importance of Nitrogen

“…Along this review I have highlighted the key role played by nitrogen to synthesize codoped graphene systems. Although in section I mentioned that Mn, Fe, Co, Ni, Ir, and Au metal dopants have been embedded in the graphene framework, − nitrogen has been intensively used to stabilize metals in the graphene sheet. − Among these systems Fe and N codoped graphene is one of the most studied ones, − probably because they can be used in single-atom catalysis. In 2015, Dong et al demonstrated that the latter system is a very effective catalyst for the ORR.…”