Graphene oxide soaks up radioactive waste
10 Jan 2013
Graphene oxide has a remarkable ability to quickly remove radioactive material from contaminated water, researchers at Rice University and Lomonosov Moscow State University have found.
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| Graphene oxide is added to simulated nuclear waste, which quickly clumps for easy removal. (Credit Anna Yu. Romanchuk/Lomonosov Moscow State University) |
A collaborative effort by the Rice lab of chemist James Tour and the Moscow lab of chemist Stepan Kalmykov determined that microscopic, atom-thick flakes of graphene oxide bind quickly to natural and human-made radionuclides and condense them into solids. The flakes are soluble in liquids and easily produced in bulk.
The experimental results were reported in the Royal Society of Chemistry journal Physical Chemistry Chemical Physics.
The discovery, Tour says, could be a boon in the cleanup of contaminated sites like the Fukushima nuclear plants damaged by the 2011 earthquake and tsunami. It could also cut the cost of hydraulic fracturing (''fracking'') for oil and gas recovery and help reboot American mining of rare earth metals, he adds.
Graphene oxide's large surface area defines its capacity to adsorb toxins, Kalmykov says. ''So the high retention properties are not surprising to us,'' he said. ''What is astonishing is the very fast kinetics of sorption, which is key.''
''In the probabilistic world of chemical reactions where scarce stuff (low concentrations) infrequently bumps into something with which it can react, there is a greater likelihood that the 'magic' will happen with graphene oxide than with a big old hunk of bentonite,'' says 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 researchers. ''In short, fast is good.''
