Encapsulation of metal nanoparticles at the surface of a prototypical layered material

Abstract

Metal nanoclusters encapsulated beneath the graphite surface present novel surface nanostructures and open opportunities to investigate and control interfacial properties.

Dy adsorption on and intercalation under graphene on 6 H -SiC(0001) surface from first-principles calculations

“…The optB88-vdW functional [40] is used for electron-electron exchange correlations. This functional includes the vdW interactions, and its application for various vdW materials with metals [28][29][30][31][32][33][34][35][41][42][43] has already been proven very successful. A benchmark analysis for bulk properties of 6H-SiC and hexagonal close-packed (hcp) Dy is provided in Appendix A with the reasonable results.…”

“…Knowledge of energetics for a single isolated atom at the surface of a layered material is fundamental to assess the thermodynamic preference of intercalation vs adsorption for the guest atom [28,29,[32][33][34][35]42,43], as well as related kinetic processes [27,51]. Predicting the geometric structure after the guest atom intercalates into the layered material is also instructive, e.g., interlayer spacings and surface corrugations can be experimentally measured as basic structural parameters.…”

“…For multiple metal guest elements, it was recently demonstrated that it is difficult or impossible to directly penetrate the perfect TLG of graphite into the gallery beneath the TLG in the typical experimental temperature range <1500 K. This feature likely reflects a large energy barrier for the penetration. Thus, to effectively realize metal intercalation under the surface of graphite, a preprepared ion-bombarded graphite surface is always needed, where the guest metal atoms (e.g., Dy, Cu, Ru, Fe, and Pt) can intercalate through the portal defects [27][28][29][30][31][32][33][34][35]. However, previous experiments (including our own experiments for rare-earth metals Dy, Eu, and Gd [36,37]) show that many types of guest elements can intercalate into epitaxial graphene on a SiC substrate [4] without a preprepared ion-bombarded top surface.…”

Thermodynamically Driven Formation of Intercalated Cu Carpets from Supported Cu Pyramids on MoS2

“…Intercalation of foreign guest species in transition metal dichalcogenides (TMDs), such as MoS 2 , WS 2 , MoSe 2 , WSe 2 , et al, is beginning to attract considerable interest. This is in part due to the novel electronic properties of these systems enabling prospective applications to high-performance electronics, optoelectronics, electrochemical catalysis, energy storage and conversion (such as ionic batteries), and biological systems. − In this context, studies of intercalation specifically for MoS 2 have attracted considerable attention. , On the other hand, TMD nanosheets are often fabricated by intercalation, and various methods toward this goal have been utilized. , Also, there do already exist extensive studies of near-surface intercalation in other types of layered van der Waals (vdW) materials, including graphite (or multilayer graphene) and SiC- , or metal-supported graphene layers. The above studies − generally involve homogeneously distributed intercalant atoms in the TMD interlayer spaces.…”

“…Recently, Cu intercalation in a TMD was successfully achieved by Cu deposition at around 1000 K on a 2 H -MoS 2 substrate which was Ar-ion bombarded to create surface point defects . This study employed a similar strategy to previous efforts on intercalating Cu , and other metals including Dy, Ru, Fe, and Pt in graphite . Cu deposition on 2 H -MoS 2 leads to the formation of supported clusters with various growth shapes including pyramids .…”