Understanding Nanotechnology  

Graphene Oxide

The properties of graphene oxide have caused researchers and companies to consider using this material in several fields. The following survey of research activity introduces you to many potential applications of graphene.

A Survey of Graphene Oxide Applications

Reseachers at Lawrence Berkeley National Laboratory have demonstrated a lithium-sulfur battery that uses a cathode made from graphene. Initial results show the battery to have significantly higher energy density and lifetime than lithium ion batteries.

Using graphene oxide to remove radioactive material from water. Researchers found that flakes of graphene oxide absorbs radioactive ions in water. The graphene oxide then forms clumps that can be removed from the water for disposal.

Researchers at the University of Michigan are developing a sensor that can detect a very low level of cancer cells, as low as 3 to 5 cancer cells in a one milliliter in a blood sample. They grow sheets of graphene oxide, on which they attach molecules containing an antibody that attaches to the cancer cells. They then tag the cancer cells with fluorescent molecules to make the cancer cells stand out in a microscope.

Using graphene oxide as a electrically insulating layer in which conductive graphene nanowires can be written. Since the oxygen in graphene oxide is removed when heat is applied with a atomic force microscope tip, resulting in conductive nanowires. This shows the possibility of writing conductive circuits in the insulating graphene oxide film.

Adding graphene oxide to sand to enhances the ability of sand filters to remove pollutants from water. The graphene oxide coats grains of sand, and contaminates in the water attach to the graphene oxide. Tests with mecury contaminated water showed that while uncoated sand saturated in 10 minutes the sand coated with graphene oxide took 50 minutes to saturate.

Researchers are using graphene oxide to produce anodes for lithium-ion batteries that recharge faster. They quickly heat the graphene oxide, which results in oxygen escaping from the film. The oxygen is driven off fast enough to cause fractures and voids in the film, which without the oxygen is graphene, which is an electrical conductor. The fractures and voids in the graphene film allow lithium ions quick entry, resulting in faster charge and discharge times for batteries.

Compiled by Earl Boysen of Hawk's Perch Technical Writing, LLC and UnderstandingNano.com. You can find him on Google+.