The new method, explained in the Physical Chemistry Chemical Physics Journal, proves that microscopic, atom-thick flakes of graphene oxide can bind quickly to natural and human-made radionuclides and condense them into solids for easy removal from contaminated water.

Rice University chemist James Tour and Lomonosov Moscow State University academic Stepan Kalmykov believe the discovery could be used in the clean-up of contaminated sites, such as the Fukushima nuclear plants damaged by a 2011 earthquake and tsunami, according to the statement released yesterday.

The researchers focused on removing radioactive isotopes of the actinides and lanthanides – the 30 rare earth elements in the periodic table – from liquids, rather than solids or gases.

“Though they don’t really like water all that much, they can and do hide out there,” said Steven Winston, a former vice-president of Lockheed Martin and Parsons Engineering and an expert in nuclear power and remediation who is working with the scientists.

“From a human health and environment point of view, that’s where they’re least welcome,” he added.

Key benefits for mining

Naturally occurring radionuclides are also unwelcome in fracking fluids that bring them to the surface in drilling operations, Tour said. “When groundwater comes out of a well and it’s radioactive above a certain level, they can’t put it back into the ground,” he said. “It’s too hot. Companies have to ship contaminated water to repository sites around the country at very large expense.”

The ability to quickly filter out contaminants on-site would save a great deal of money, he said.

He sees even greater potential benefits for the mining industry. Environmental requirements have “essentially shut down US mining of rare earth metals, which are needed for cellphones,” Tour said. “China owns the market because they’re not subject to the same environmental standards. So if this technology offers the chance to revive mining here, it could be huge.”

Medicine

The biomedical field is also looking at graphene’s applications for advancing therapeutics and diagnostics. An article in the journal Advanced Materials (“New Horizons for Diagnostics and Therapeutic Applications of Graphene and Graphene Oxide“) outlines some of the ways the element and its oxide are promising improved diagnostics and therapeutics for a number of different health conditions.

Graphene is also being looked at for drug and gene delivery applications, phototherapy for cancer and biosensors. In particular, researchers have been experimenting with combining graphene with near-Infrared (NIR) phototherapy and imaging. There has been some progress in using graphene-enabled NIR photo-thermal therapy for cancer and Alzheimer’s disease (AD).

While both pure graphene and graphene oxide have exhibited some toxicity to cells and animals, experts say that coating it with a biocompatible polymer results in no detectable toxicity in both cellular and animal testing.