Deoxygenation Enhances the Quality of Graphene in Mass Production

Graphene, often hailed as the “miracle material of the 21st century,” has been praised for its numerous unique properties since its discovery in 2004. However, a significant drawback of currently mass-produced graphene is its subpar quality.

Now, a joint research team from Columbia University in the United States and the University of Montreal in Canada has developed a new method to purify graphene using oxygen-free chemical vapor deposition (OF-CVD). This advancement allows for the mass production of high-quality graphene. The relevant paper was published on the 29th in the journal Nature.

Research Highlights

The Hone Laboratory at Columbia University utilized the OF-CVD method to create over 100 identical graphene samples. This research demonstrates how trace amounts of oxygen influence the growth rate of graphene and, for the first time, establishes the connection between oxygen levels and graphene quality. The experiments show that removing oxygen during the growth process is crucial for synthesizing high-quality graphene using the CVD method. This finding could be a milestone towards the mass production of graphene.

CVD Method and Its Challenges

Approximately 15 years ago, researchers developed a method to synthesize large-area graphene, known as the chemical vapor deposition (CVD) growth method, to transition graphene production from the lab to practical applications. In this process, at sufficiently high temperatures (around 1000°C), carbon-containing gases (such as methane) pass over a copper surface, causing the methane to decompose, and carbon atoms rearrange to form a single-layer hexagonal graphene sheet. While the CVD growth method can scale up to produce graphene samples several centimeters to even meters in size, the quality of CVD-synthesized samples often suffers from inconsistency and instability.

Innovations and Results

The research team found that removing trace amounts of oxygen significantly accelerates the growth rate of graphene. Further analysis led them to develop a simple model that can predict the growth rate of graphene under different parameters (such as pressure and temperature). By improving the existing CVD system, they produced graphene of very high quality, comparable to graphene obtained by the mechanical exfoliation method (often referred to as the “Scotch tape method”). The high-quality graphene exhibited fractional quantum Hall effects in a magnetic field.

Conclusion

The study marks a significant advancement in understanding the role of oxygen in graphene growth and demonstrates a method for producing high-quality graphene on a large scale. This development could pave the way for the broader application of graphene in various industries.

Source: Graphene Yellow Pages