Rutgers University engineers have found a method for producing high-quality graphene that can be used in next-generation electronic and energy devices: bake the compound in a microwave oven.
“This simple microwave treatment leads to exceptionally high-quality graphene with properties approaching those in pristine graphene,” says Manish Chhowalla, professor in the university's Department of Materials Science and Engineering.
Graphene is up to 100 times stronger than steel and conducts electricity better than copper and rapidly dissipates heat, making it useful for many applications. Large-scale production of graphene is necessary for applications such as printable electronics, electrodes for batteries, and catalysts for fuel cells.
Perhaps the easiest way to make large quantities of graphene is to exfoliate graphite into individual graphene sheets via the use of chemicals. The downside is that side reactions occur with oxygen, forming graphene oxide that is electrically non-conducting. This makes it less useful for products.
Removing oxygen from graphene oxide to obtain high-quality graphene has been a challenge over the past two decades for the scientific community. Oxygen distorts the pristine atomic structure of graphene and degrades its properties.
Chhowalla and his group found that baking the exfoliated graphene oxide for 60 seconds in a 1,000-watt microwave oven can eliminate virtually all of the oxygen from graphene oxide.