Microwaves make better graphene

MICROWAVES could solve many of the problems related to industrial, high-quality graphene production, according to engineers in the Republic of Korea and the US.

A common way to produce graphene is to ‘exfoliate’ individual graphene layers from graphene in solution. However, this method generates significant quantities of graphene oxide layers as well, distorts the structure and degrades the quality of the graphene. Removing the oxygen is difficult and has been a significant research challenge. The team of researchers from Ulsan National Institute of Science and Technology (UNIST) and Rutgers University say that using microwaves can remove the oxygen.

Researcher Jieun Yang and her team expose graphene oxide to 1–2 second pulses of microwaves. Yang explains that the partially-reduced graphene oxides absorb the microwave energy, resulting in the elimination of virtually all of the oxygen functional groups. In addition, the technique causes the damaged and defective graphene films to rearrange into a regular structure.

The treated graphene has an oxygen content of below 4%. Conventionally-produced graphene generally contains 15–25% oxygen.

“The current method for mass-producing high-quality graphene lacks reproducibility, but holds huge untapped market potential. Therefore, securing the fundamental technology for mass production of graphene is an extremely important matter in terms of commercialising future promising industries,” said researcher and UNIST associate chemistry professor Hyeon Suk Shin.

Science DOI: 10/bvv4