Microwaves used to produce 'high quality' graphene for electronics
Baking graphene in a microwave oven has been shown to imbue it with properties that make it perfect for next-generation electronic and energy devices.
Graphene, which is 100 times tougher than steel, conducts electricity better than copper and rapidly dissipates heat, making it useful for many applications.
Large-scale production of graphene will become necessary for applications such as printable electronics, electrodes for batteries and catalysts for fuel cells.
Graphene comes from graphite, a carbon-based material that is typically found in pencils and consists of sheets or layers of graphene.
The easiest way to make large quantities of graphene is to exfoliate graphite into individual graphene sheets by using chemicals. The downside of this approach is that side reactions occur with oxygen, forming graphene oxide that is electrically non-conducting, which makes it less useful for products.
Removing oxygen from graphene oxide to obtain high-quality graphene has been a major challenge over the past two decades for the scientific community working on graphene. Oxygen distorts the pristine atomic structure of graphene and degrades its properties.
But a team at New Jersey’s Rutgers University led by professor Manish Chhowalla has found that baking the exfoliated graphene oxide for just one second in a 1,000-watt microwave oven, like those used in households across America, can eliminate virtually all of the oxygen from graphene oxide.
"This is a major advance in the graphene field," said Chhowalla. "This simple microwave treatment leads to exceptionally high-quality graphene with properties approaching those in pristine graphene.
“The Rutgers Materials Science and Engineering Department and the School of Engineering at Rutgers cultivate a culture of curiosity driven research in students with fresh ideas who are not afraid to try something new,” he added.
In March, another team demonstrated how crumpling and creasing graphene could significantly improve its water-resisting and electrochemical properties.