  The ability to pattern graphene at low temperatures in a scalable manner is
one of the greatest challenges facing graphene industrial adoption today. We
demonstrate a simple method for low-temperature gold-catalyzed etching of
graphite with predictable characteristics using ambient air at $350-375^\circ$
C. 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 $375^\circ$ C is required to obtain
single-layer deep etching. 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.
