3 Ways to Produce Graphene

Posted by Rob A on September 14th, 2019

Graphene is a revolutionary material that has incredible properties, such as excellent strength and conductivity. Although scientists have yet to find an effective method for mass-producing this single-atom carbon lattice, they've discovered several ways to synthesize it and create small sheets. Here are a few of them.

Chemical Vapor Deposition (CVD)

It's the most common way to produce this material. CVD growth of graphene is the process that has synthesized the largest sample sizes on average. It's a form of epitaxy, which is the method of depositing a crystalline layer over a base or a substrate matter. In this case, the graphene coating will be accumulated on a metal-like copper using chemical vapor.

Different volatile gas molecules are placed in a reaction chamber along with the base on which a sheet of material will form. This enclosure is then heated. As the high temperature decomposes these gases, they'll slowly create a film as they come into contact with the metal substrate.

Graphene CVD is known to create high-quality products. Sheets made from this process have higher purity, increased impermeability, and greater strength than ones made with other methods.

Exfoliation through Oxidation

Another way to produce this substance is through exfoliation. The discovery of graphene, which was done through continuously pulling off layers of pencil lead with a piece of tape, is actually a form of exfoliation. There are many methods included in this category, the most popular of which is oxidation.

In this method, graphite oxide is reduced into graphene oxide. The process often involves exposing the material to strong oxidizing substances, like sulfuric acid. They react with the graphite, and the spaces between its layers increase. The product will be dipped in water, and then shed from the solution to create graphene oxide.

Exfoliation through Mechanical Cleavage

An alternate way of exfoliation is through wedging or mechanical cleavage. In this process, the single-atom carbon lattice is created from bulk graphite. It uses an extremely sharp single-crystal diamond wedge to cut into the material and exfoliate a layer of graphene.

Unlike the other methods, this process only creates flakes and not sheets. But this approach is definitely more cost-effective and has many potential industrial applications.

From CVD growth of graphene to the different exfoliation techniques, there are many ways to create this wonder material. Though none of them have made large quantities in one go, scientists are continually developing new methods. Someday, they'll find one that's fit for mass production.