For more than a thousand years, humans have dreamed of
transforming a worthless substance (lead) into something precious
(gold). But in the 21st century, the mythical philosophers’ stone
might produce not gold, but graphene, a two-dimensional carbon
nanomaterial with so many industrial uses that it’s
more valuable by weight than the 24 karat stuff. And that
transformation may no longer be a fantasy. Researchers
at Rice University have devised a technique that seems akin to
modern-day alchemy for making graphene from garbage.
Since graphene was discovered in 2004, demand for the material
skyrocketed thanks to its remarkable physical qualities. With
its single layer of carbon atoms, graphene is at least 100 times
stronger than steel, ultra-light, as stretchy as rubber, and the
best heat conductor in the world. But the supply of graphene has
been limited by the painstaking processes used for producing it in
the lab, from expensive chemical reactions to grinding away at
layers of graphite — yes, the stuff from pencils —on the atomic
The new study
shows that a split-second, ultra-hot flash of electricity focused
on any item containing carbon — say, an old sandwich, a plastic
water bottle, or a worn out rubber tire — can also produce
graphene by forcing all the other elements to escape as gases,
leaving behind only a two-dimensional, ultra-strong carbon lattice.
The burst of energy that heats up the item to over 5000 degrees F
is so precisely concentrated that making a pound of this “flash
graphene” would only use the same amount of energy as running a
typical dishwasher for half an hour.
James Tour, one of the study’s authors, explains that
transforming the carbon found in food or trash into graphene keeps
that carbon from reentering the atmosphere as the items decompose.
“We bring up a lot of assets from under the ground, a lot of
carbon in the form of coal, oil, and gas … [and] that carbon
becomes part of our world,” he said. “But when you make
graphene, it’s fixed. It doesn’t enter the carbon cycle
The idea of turning waste into graphene
isn’t new, but this is the first time researchers have made
the transformation a reality. If the flash graphene method can be
scaled up, the discovery could transform graphene from a luxury
material hiding in laboratories and some niche products into a
common component in a wide variety of industries, including
medicine, buildings, batteries, and electronics.
Climate-wise, one of graphene’s most exciting applications is
also one of the lowest-tech. Cement produces 8 percent of the
world’s carbon emissions —
triple what the global aviation sector emits — but mixing in
just 0.1 percent of flash graphene can slash those emissions by a
third. If all the cement in the world were produced with flash
graphene, that would be like erasing the annual carbon emissions of
Tour, who is also a scientific advisor for a company called
Universal Matter that’s trying to produce flash graphene
commercially, also points out that flash graphene made from food
waste has the added climate benefit of reducing
emissions from methane, a potent greenhouse gas released as
food rots in landfills.
While the new method represents a breakthrough in graphene
production, questions remain about whether flash graphene can
scale. The Rice researchers have produced mere grams of graphene,
and Zhongfan Liu, a graphene researcher at Peking University who
was not involved in the study, cautions that “going from the gram
level, kilogram level, up to the ton level is still a long way.”
And Claire Berger, a researcher who specializes in graphene for
electronics at Georgia Tech, emphasizes that
not all forms of graphene are interchangeable, which might
limit flash graphene’s usefulness. You wouldn’t use the same
kind of graphene in cement as in a sensitive electronic or
biomedical device, for instance.
Any scaling effort would also have to trap the elements besides
carbon from the original item, such as silicon or aluminum, which
the flash method releases as gas. Tour doesn’t see disposing of
these leftover elements as a barrier; he even speculates that
selling them back to the chemical industry would even help make
flash graphene more scalable in bulk.
Dru Kefalos, Universal Matter’s chief marketing officer,
acknowledges that flash graphene “is still an early stage
invention” but says that the company is moving rapidly to expand
and expects to build their first industrial-scale production plant
by late 2021.
In the first Harry Potter book, the philosopher’s stone is
ultimately destroyed because it turns out that having an alchemical
panacea lying around can backfire. Likewise, even in a best-case
scenario with flash graphene, sitting around and waiting for
production to take off doesn’t seem like a good solution for
massive global waste problem or cutting carbon emissions. But
it may have the potential to play a role in fighting both problems
— more like a helpful house elf, perhaps, than a magical answer
to make our trash or emissions go away.
This story was originally published by Grist with the headline
This ultra-strong nanomaterial could cut carbon emissions — and
it’s made out of garbage on Feb 10, 2020.
Source: FS – All – Science – News
This ultra-strong nanomaterial could cut carbon emissions — and it’s made out of garbage