Any reader well-read enough in the field of experimental engineering studies through websites or magazines will no doubt be familiar with the name graphene. The famous carbon allotrope, consisting of one or more layers of carbon atoms arranged in a honeycomb lattice, has been touted as a “material of the future,” promising tantalizing applications in structural and electronic components, among other things, due to its unique mix of properties. Of course, reality is often not as simple as research articles claim, and we really don’t see graphene being used everywhere just yet—a fact attributed to many limiting factors, one of which being its methods of production. One study, published in ACS Nano, attempted to address one of these factors: production speed.
Researchers from Rice University used “flashes of electricity” to heat carbon sources, manipulating the duration of the flash to control what final form the carbon ends up in. The newly-developed method, coined “flash Joule heating” (FJH), passes an electrical current through the carbon source for around 10 milliseconds, heating it to temperatures around 2,727 °C (4,940 °F). Initially developed around January 2020, the method converted these sources into pristine, turbostratic graphene flakes—or graphene flakes whose basal planes are out of alignment.
Further development of FJH led to improvements in the process through the months. By increasing the flash duration between 10 and 500 milliseconds, the research team created other forms of carbon instead, like nanodiamonds and a form they coined “concentric carbon,” or a form where a nanodiamond is surrounded by a shell of carbon atoms. “Concentric carbon” was mentioned to be useful as a possible lubricant additive.
The team also tested adding fluorine to the source mix—from organic fluorine compounds—as previous studies had already addressed the presence of fluorine helping in clumping carbon atoms together, thereby skipping the otherwise high pressures necessary to generate diamonds from carbon through standard methods. As a result, FJH allowed the production of fluorinated versions of their previous results, including fluorinated nanodiamonds—promising possible usage of FJH for the semiconductor industry.
The team hopes that further developments in the process can help produce functional carbon materials by adding more additives such as boron and phosphorus to skip a few steps on alternative and otherwise traditional production methods.
Bibliography
- Irving, M. (2021, June 21). New method converts carbon into graphene or diamond in a flash. New Atlas. Retrieved August 27, 2021, from https://newatlas.com/materials/carbon-graphene-diamond-flash-joule-heating/
- Chen, W., Li, J. T., Wang, Z., Algozeeb, W. A., Luong, D. X., Kittrell, C., … & Tour, J. M. (2021). Ultrafast and Controllable Phase Evolution by Flash Joule Heating. ACS Nano.
