This visualization shows layers of graphene used for membranes. Image credit: University of ManchesterUniversity of Arkansas researchers have discovered a simple and scalable method for turning graphene oxide into a non-flammable and paper-like graphene membrane that can be used in large-scale production.

Graphene's extremely high flammability has been an obstacle to further development and commercialization. However, this new discovery makes it possible to mass-produce graphene and graphene membranes to improve a host of products, from fuel cells to solar cells to supercapacitors and sensors.

Using metal ions with three or more positive charges, researchers bonded graphene-oxide flakes into a transparent membrane. This new form of carbon-polymer sheet is flexible, nontoxic and mechanically strong, in addition to being non-flammable.

Further testing of the material suggested that crosslinking, or bonding, using transition metals and rare-earth metals, caused the graphene oxide to possess new semiconducting, magnetic and optical properties.

For the past decade, scientists have focused on graphene, a two-dimensional material that is a single atom in thickness, because it is one of the strongest, lightest and most conductive materials known. For these reasons, graphene and similar two-dimensional materials hold great potential to substitute for traditional semiconductors. Graphene oxide is a common intermediate for graphene and graphene-derived materials made from graphite, which is a crystalline form of carbon.

The researchers' findings were published in The Journal of Physical Chemistry C.