Yes, we can, by 2D structure.

Dear Kumar,

Carbon has many allotropes. The nanosheet defined a 3D system that one its dimension has a ultrathin thickness. Thus, we could say that diamond ultrathin film, Graphene, Graphane, Graphyne structures are carbon nanosheets.

There is a recent article trying to unify the new carbon nomenclature, it is free to download:

"All in the graphene family – A recommended nomenclature for two-dimensional carbon materials" by Alberto Bianco, Hui-Ming Cheng, Toshiaki Enoki, Yury Gogotsi, Robert H. Hurt, Nikhil Koratkar, Takashi Kyotani, Marc Monthioux, Chong Rae Park, Juan M.D. Tascon and Jin Zhang. It appears in Carbon, Volume 65, December 2013, Pages 1-6 (2013)

Thank you Dr Briones, it was a good article.

Thank you for this very nice link @ F.C.Briones and all the discussion was nice on this

Carbon nanosheets or carbon nanowalls - these terms coined by M. Zhu et al ( DOI: 10.1016/j.carbon.2004.06.035) and Wu et al (DOI: 10.1002/1521-4095(20020104)14:13.0.CO;2-G). These carbon nanostructure also known as vertical graphene, graphene nanowalls/nanosheets, few layer graphene. By their definition, it is nothing but interconnected vertically oriented few layer graphene network. Now question is can we use graphene as a carbon nanosheets? But recent article, mentioned by Briones, not defined this kind of structures (carbon nanosheets).