Since the early stage of the graphene production, quality was pointed out as one of the main issues to be solved in the future. Even from the academic point of view the quality of graphene and other 2D materials has not yet reached an unanimity. On the other extreme, many companies popped-up all around the world in recent years, offering all sort of graphene “products”. So how to insure that what you are buying to do your R&D is really graphene?
Taking in consideration our definition of graphene (10 layers or less) we have tested different graphene products (powder and solutions) from more than 30 companies, using academically accepted protocols. In this study we evaluated their quality in terms of number of layers, flake (crystallite) size, spectral quality (Raman), chemical purity, and other characteristics.
Here are some of our findings.
The grey areas represent the average and two standard deviations (m ± 2σ, or 95% of the population in a Gaussian distribution) of the numbers of layers (X axis) and crystallite size (Y axis) found for every tested Graphene product (products with more than 300 layers are not shown).
Also, many institutions, such as The Graphene Council, Graphene Flagship, Graphene-Info, and International Organization for Standardization (ISO), have highlighted the need of Graphene Standards to enable more effective developments in this area.
And yes, you are probably buying Graphite!