News from outside the GLADIATOR project: in Science volume 342 number 6159 pp. 720-723 (2013) Yufeng Hao and co-authors at the University of Texas reported that oxygen can reduce CVD graphene nucleation density on copper growth catalysts, thus influencing the shape of the resulting graphene crystals and improving the electrical quality of the film so produced.
For more information see this article at SciTech daily, or the publication itself.