Characterization of Au catalytic activity in low-temperature graphene etching

Abstract

Recent research into Au nanoparticles has revealed some surprising catalytically favorable properties. We apply these properties to the signficant challenge of patterning graphene at low temperatures in a scalable manner. By utilizing these Au nanoparticles, we demonstrate a simple method for low-temperature gold-catalyzed etching of graphite with predictable characteristics using ambient air at 350–375 °C and an ability to etch only the top graphene layer of a graphite piece with suitable choice of processing steps. The naturally occurring water vapor in ambient air is necessary for this reaction to occur. In addition, we characterize the etch characteristics as a function of process parameters. Ar annealing is required to obtain crystallographically straight etches, and 375 °C may be required to obtain single-layer deep etching. The catalytic activity is around ∼1μmolC/gAus and terminates due to catalyst poisoning around ∼0.7mmolC/gAu. We hypothesize that enhanced nanoparticle size control will have the greatest effect on catalytic activity. We anticipate that this work can be adapted by future research to precisely control the shape of the etched areas, allowing for the simple low-temperature creation of nanoscale graphite features, and ultimately can be applied to single-layer graphene sheets for integrated device fabrication.