|The new molecule employs a nanographene complex (on left) to absorb light and drive the conversion of carbon dioxide (upper center) to carbon monoxide (on right). Credit: Ben Noffke and Richard Schaugaard, Indiana University|
“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.”
|An alternate version of the molecule, NGReCO2. Credit: Indiana University|
“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.”
Essentially, Li said, the molecule acts as a two-part system: a nanographene “energy collector” that absorbs energy from sunlight and an atomic rhenium “engine” 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.
“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.