Wetting and energetics in nanoparticle etching of graphene

Abstract

Molten metallic nanoparticles have recently been used to construct graphene nanostructures with crystallographic edges. The mechanism by which this happens, however, remains unclear. Here, we present a simple model that explains how a droplet can etch graphene. Two factors possibly contribute to this process: a difference between the equilibrium wettability of graphene and the substrate that supports it, or the large surface energy associated with the graphene edge. We calculate the etching velocities due to either of these factors and make testable predictions for evaluating the significance of each in graphene etching. This model is general and can be applied to other materials systems as well.As an example, we show how our model can be used to extend a current theory of droplet motion on binary semiconductor surfaces.

Nature of Graphene Edges: A Review

“…7(a) and 7(b)]. 89) Loop formation is another way to modify edge reconstruction. It is a surface-driven process, in which reactive edges, sp 2 -hybridized surfaces and interfaces play a role.…”

The Nanoparticle Size Effect in Graphene Cutting: A “Pac‐Man” Mechanism

“…[14] To better control the cutting process,t he underlying atomic mechanisms should be understood. [21][22][23][24] Currently,the unzipping mechanism [7,[25][26][27] is the dominant graphene-cutting mechanism reported in the literature,w here C À Cb onds in graphene are broken by single cutting atoms and the nanoparticle size is thus irrelevant. However,s ignificant nanoparticle size effects on both the cutting behavior and the resulting graphene edge morphology have been observed experimentally.…”

The Nanoparticle Size Effect in Graphene Cutting: A “Pac‐Man” Mechanism

“…[14] To better control the cutting process, the underlying atomic mechanisms should be understood. [21][22][23][24] Currently, the unzipping mechanism [7,[25][26][27] is the dominant graphene-cutting mechanism reported in the literature, where C À C bonds in graphene are broken by single cutting atoms and the nanoparticle size is thus irrelevant. However, significant nanoparticle size effects on both the cutting behavior and the resulting graphene edge morphology have been observed experimentally.…”