Researchers have discovered a new way to take some of the atmospheric carbon dioxide from the atmosphere and use it to make an advanced, high-value material for use in energy storage products.

This innovation in nanotechnology will provide an environmentally friendly, low-cost way to make nanoporous graphene for use in supercapacitors, devices that can store energy and release it rapidly. Such devices are used in everything from heavy industry to consumer electronics.

The findings were published in Nano Energy by scientists from the Oregon State University College of Science, OSU College of Engineering, Argonne National Laboratory, the University of South Florida and the National Energy Technology Laboratory.

In the chemical reaction that was developed, the end result is nanoporous graphene, a form of carbon that’s ordered in its atomic and crystalline structure. It has an enormous specific surface area of about 1,900 square meters per gram of material. Because of that, it has an electrical conductivity at least 10 times higher than the activated carbon now used to make commercial supercapacitors.

“There are other ways to fabricate nanoporous graphene, but this approach is faster, has little environmental impact and costs less,” says Xiulei (David) Ji, an OSU assistant professor of chemistry and lead author on the study. “The product exhibits high surface area, great conductivity and, most importantly, it has a fairly high density that is comparable to the commercial activated carbons.

Because the materials involved are inexpensive and the fabrication is simple, this approach has the potential to be scaled up for production at commercial levels, researchers say.

The chemical reaction involved a mixture of magnesium and zinc metals. These are heated to a high temperature in the presence of a flow of carbon dioxide to produce a controlled “metallothermic” reaction. The reaction converted the elements into their metal oxides and nanoporous graphene, a pure form of carbon that’s strong and can efficiently conduct heat and electricity. The metal oxides could later be recycled back into their metallic forms to make an industrial process more efficient.

“Most commercial carbon supercapacitors now use activated carbon as electrodes, but their electrical conductivity is very low,” Ji says. “We want fast energy storage and release that will deliver more power, and for that purpose the more conductive nanoporous graphene will work much better. This solves a major problem in creating more powerful supercapacitors.”