How to differentiate Graphene : Production processes

09 Jun How to differentiate Graphene

Posted at 11:52h in News by Dia

Explaining how Graphene is produced

Graphene was isolated by the scotch-tape method for the first time in the world in 2004. This method proved that graphene was not only a theory, but a reality.

The scotch-tape method is absolutely not transferable for an industrial production of graphene. But it was a stepping-stone, and several different production processes emerged since the first isolation of graphene.

Two different strategies can be applied:

1-Bottom Up:

Graphene produced from gases by Chemical Vapour Deposition (CVD)

2-Top Down:

Graphene produced from graphite by exfoliation (chemical, mechanical, oxidative)

These different production processes give various graphene forms.

We can segment the graphene family in 2 ways:

Thickness of the material

Purity of graphene

Thickness of the material

Graphene is limited to 10 layers, so less than 3nm thick. Nowadays, very few companies are able to produce such a graphene.

SLG: Single Layer Graphene (1 Layer)
FLG: Few Layer Graphene (2-5 Layers)
MLG: MultiLayer Graphene (<10 Layers)
GNP: Graphite NanoPlates (<250 Layers)

For such a 2D material, thickness is a critical parameter. The thinnest the material, the better the properties will be!

Purity of Graphene

Functional groups, even in low quantity, decrease the performance as anticorrosion agent or thermal and electrical conductor.

The degree of functionalization and the level of defects, depend strongly on the method of production!

Chemical Vapour Deposition Graphene (CVD)

SLG or FLG with nearly no functional groups or defects

Chemically Exfoliated Graphene

FLG or MLG with very low amount of functional groups and defects

Mechanical Exfoliated Graphene

FLG, MLG or GNP with low amount of functional groups and defects

Reduced Graphene Oxide (rGO)

SLG, FLG, MLG or GNP with functional groups and defects

Graphene Oxide (GO)

FLG, MLG or GNP with many functional groups and defects

PURITY DECREASE

Comparing Graphene

When choosing graphene, you should be careful of the quality and scalability of the graphene. It all depends on the application and how you want to use graphene.

Processes	Thickness	% Purity	Scalability
CVD	1 Layer	> 99.99%	–
Chemical exfoliation*	2-8 Layers	> 99.95%	++
Mechanical exfoliation	2-249 Layers	> 99%	++
rGO	1-249 Layers	95% < rGO < 99%	++
GO	2-249 Layers	< 80%	++