A method includes producing deposition conditions in a collection area above a reactant liquid containing one or more catalyst metals. The reactant liquid is maintained under conditions in which atoms of the catalyst metal may escape from the reactant liquid into the collection area. A suitable carrier gas is directed to traverse a surface of the reactant liquid and flow along a collection path that passes over a collection surface in the collection area. This flow of carrier gas is maintained so that escaped atoms of catalyst metal are entrained in the gas traversing the surface of the reactant liquid and are deposited on the collection surface prior to or concurrently with nanocarbon structure formation at the collection surface.