How To Recycle Carbon Dioxide

An international team of scientists led by Liang-shi Li at Indiana University (IU) has achieved a new milestone in the quest to recycle carbon dioxide in the Earth’s atmosphere into carbon-neutral fuels and others materials.


The chemists have engineered a molecule that uses light or electricity to convert the greenhouse gas carbon dioxide into carbon monoxide — a carbon-neutral fuel source — more efficiently than any other method of “carbon reduction.”

molecular leaf

If you can create an efficient enough molecule for this reaction, it will produce energy that is free and storable in the form of fuels,” said Li, associate professor in the IU Bloomington College of Arts and Sciences‘ Department of Chemistry. “This study is a major leap in that direction.”

Burning fuel — such as carbon monoxide — produces carbon dioxide and releases energy. Turning carbon dioxide back into fuel requires at least the same amount of energy. A major goal among scientists has been decreasing the excess energy needed.

This is exactly what Li’s molecule achieves: requiring the least amount of energy reported thus far to drive the formation of carbon monoxide. The molecule — a nanographene-rhenium complex connected via an organic compound known as bipyridine — triggers a highly efficient reaction that converts carbon dioxide to carbon monoxide. The ability to efficiently and exclusively create carbon monoxide is significant due to the molecule’s versatility.

Carbon monoxide is an important raw material in a lot of industrial processes,” Li said. “It’s also a way to store energy as a carbon-neutral fuel since you’re not putting any more carbon back into the atmosphere than you already removed. You’re simply re-releasing the solar power you used to make it.

The secret to the molecule’s efficiency is nanographene — a nanometer-scale piece of graphite, a common form of carbon (i.e. the black “lead” in pencils) — because the material’s dark color absorbs a large amount of sunlight.

Li said that bipyridine-metal complexes have long been studied to reduce carbon dioxide to carbon monoxide with sunlight. But these molecules can use only a tiny sliver of the light in sunlight, primarily in the ultraviolet range, which is invisible to the naked eye. In contrast, the molecule developed at IU takes advantage of the light-absorbing power of nanographene to create a reaction that uses sunlight in the wavelength up to 600 nanometers — a large portion of the visible light spectrum.

Essentially, Li said, the molecule acts as a two-part system: a nanographeneenergy collector” that absorbs energy from sunlight and an atomic rheniumengine” that produces carbon monoxide. The energy collector drives a flow of electrons to the rhenium atom, which repeatedly binds and converts the normally stable carbon dioxide to carbon monoxide.

The idea to link nanographene to the metal arose from Li’s earlier efforts to create a more efficient solar cell with the carbon-based material. “We asked ourselves: Could we cut out the middle man — solar cells — and use the light-absorbing quality of nanographene alone to drive the reaction?” he said.

Next, Li plans to make the molecule more powerful, including making it last longer and survive in a non-liquid form, since solid catalysts are easier to use in the real world.

The process is reported in the Journal of the American Chemical Society.


Nano-Reactor Produces Hydrogen

Scientists at Indiana University (IU) have created a highly efficient biomaterial that catalyzes the formation of hydrogen — one half of the “holy grail” of splitting H2O to make hydrogen and oxygen for fueling cheap and efficient cars that run on water. A modified enzyme that gains strength from being protected within the protein shell — or “caps id” — of a bacterial virus, this new material is 150 times more efficient than the unaltered form of the enzyme.

indianaP22-Hyd, a new biomaterial created by encapsulating a hydrogen-producing enzyme within a virus shell.

Essentially, we’ve taken a virus’s ability to self-assemble myriad genetic building blocks and incorporated a very fragile and sensitive enzyme with the remarkable property of taking in protons and spitting out hydrogen gas,” said Trevor Douglas, Professor of Chemistry in the IU Bloomington College of Arts and Sciences’ Department of Chemistry, who led the study “The end result is a virus-like particle that behaves the same as a highly sophisticated material that catalyzes the production of hydrogen.”

The process of creating tahe material was recently reported in “Self-assembling biomolecular catalysts for hydrogen production” in the journal Nature Chemistry.


Blood Test Can Diagnose Pancreatic Cancer

Indiana University cancer researchers have found that a simple blood test might help diagnose pancreatic cancer, one of the most deadly forms of the disease.

In research published today in the American Journal of Gastroenterology, Murray Korc, M.D., Professor of Cancer Research at the Indiana University School of Medicine and a researcher at the Indiana University Melvin and Bren Simon Cancer Center, and colleagues found that several microRNAs – small RNA molecules — circulate at high levels in the blood of pancreatic cancer patients.

blood cells

This is a new finding that extends previous knowledge in this field,” Dr. Korc said. “The key new feature here is that there is a panel of microRNAs that can be measured accurately in the plasma component of blood to determine if a patient has pancreatic cancer.”

Specifically, the IU research team found that an increased expression of miRNA-10b, -155, and -106b in plasma appears highly accurate in diagnosing pancreatic ductal adenocarcinoma. Pancreatic ductal adenocarcinoma is by far the most common type of pancreatic malignancy.