"We can make you and we can break you." If Rice University scientists wrote country songs, their ode to graphene oxide would start something like that. But this song wouldn't break anybody's heart.
A new paper from the lab of Rice chemist James Tour demonstrates an environmentally friendly way to make bulk quantities of graphene oxide (GO), an insulating version of single-atom-thick graphene expected to find use in all kinds of material and electronic applications.
A second paper from Tour and Andreas Lttge, a Rice professor of Earth science and chemistry, shows how GO is broken down by common bacteria that leave behind only harmless, natural graphite.
The one-two punch appears online this week in the journal ACS Nano.
"These are the pillars that make graphene oxide production practical," said Tour, Rice's T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science. The GO manufacturing process was developed as part of a research project with M-I SWACO, a Houston-based producer of drilling fluids for the petrochemical industry that hopes to use graphene to improve the productivity of wells. (Read about that here.)
Scientists have been making GO since the 19th century, but the new process eliminates a significant stumbling block to bulk production, Tour said. "People were using potassium chlorate or sodium nitrates that release toxic gases one of which, chlorine dioxide, is explosive," he said. "Manufacturers are always reluctant to go to a large scale with any process that generates explosive intermediates."
Tour and his colleagues used a process similar to the one they employed to unzip multiwalled nanotubes into graphene nanoribbons, as described in a Nature paper last year. They process flakes of graphite pencil lead with potassium permanganate, sulfuric acid and phosphoric acid, all common, inexpensive chemicals.
|Contact: David Ruth|