Can sunlight convert emissions into useful materials?

Shama Sharda has called carbon dioxide the worst culprit of global warming, a very stable, “very happy atom.”

She aims to change that.

Recently published in Journal of Physical Chemistry a, Sharda and a team of researchers from USC Whiterbie School of Engineering, C.O.₂ Convert greenhouse gases into useful materials such as fuel or consumer products ranging from pharmaceuticals to polymers.

Typically, this process requires a lot of energy. However, in the first computational study of its kind, Sharda and his team enrolled a more sustainable ally: the Sun.

In particular, they showed that ultraviolet (UV) light stimulants can be very effective in organic molecules, oligophenyls. Upon exposure to UV, oligophenylin becomes a negatively charged “ion”, easily transferring electrons to nearby molecules, such as CO.₂CO from here₂ Reactive and capable of reducing and converting items such as plastics, drugs or furniture.

“CO₂ It’s hard to do less to defame, that’s why it lives in the atmosphere for decades, “Sharda said. But this negatively charged ion also causes CO. Something as stable is also able to reduce.₂, That’s why it’s promising and why we’re studying it. “

The rapidly increasing concentration of carbon dioxide in the Earth’s atmosphere is a very urgent issue that humanity must consider in order to avoid weather destruction.

From the beginning of the industrial age, humans have been the atmospheric CO₂ By 45%, by burning fossil fuels and other emissions. As a result, the average global temperature is now two degrees Celsius warmer than in the pre-industrial era. Thanks to greenhouse gases like CO₂, Heat from the sun trapped in our atmosphere, warms our planet.

The research team of the Mork Family Department of Chemical Engineering and Materials Science led the third year Ph.D. Student Karisa Kron, supervised by Sharda, WISE Gabilan Assistant Professor. Samantha J. of Francisco Bravo Medical Magnet High School. The work was co-authored by Gomez, a U.S.C. As part of the Young Researchers program, high school students will receive STM. Allows to participate in research.

Many research teams are focusing on methods for converting COs₂ Which has been captured from emissions in fuel or carbon-based feed stocks for consumer products ranging from pharmaceuticals to polymers.

The process traditionally uses heat or electricity with a catalyst to accelerate COP.₂ Transformation into products. However, many of these methods are often energy intensive, which is not ideal for processes aimed at reducing environmental impacts. It is attractive to use sunlight instead of stimulating the catalyst molecule because it is energy efficient and sustainable.

“Most of the other ways to do this are to use metal-based chemicals and those metals are rare earth metals,” Sharda said. “They can be expensive, they’re hard to find and they can potentially be toxic.”

Sharda said this is an option to use a carbon-based organic catalyst for light auxiliary conversion. However, this method presents its own challenges, which the research team aims to address. The team uses quantum chemistry simulations to understand how an electron moves between a catalyst and a CO₂ To identify the most practical catalyst for this reaction.

Sharda said the work was the first computational study of its kind, in which researchers had not previously investigated the underlying method of moving electrons from an organic molecule such as oligophenylin.₂. The team found that they could make systemic changes to the ligophenylin catalyst, adding groups of molecules that provide specific properties when bonded with atoms, forcing electrons toward the center of the catalyst to accelerate the reaction.

Despite the challenges, Sharda is excited about the opportunities his team has.

“One of the challenges is that, yes, they can use radiation, but a small part of it is in the visible field, where you can light it for the reaction to take place,” Sharda said. “Typically, you need a UV lamp for that to happen.”

Sharda said the team is now exploring catalytic design strategies that not only lead to higher reaction rates, but also allow the molecule to be stimulated by visible light using both quantum chemistry and genetic algorithms.

The research paper marks a co-written publication in high school student Gomez’s prestigious peer-reviewed journal.

While Gomez was a senior at Bravo Medical Magnet School, she participated in the USC Young Researchers program during the summer, working in the autumn lab. She was directly guided and trained in theory and simulation by Kron. Sharda said Gomez’s contribution was so impressive that the team agreed that he deserved to be a writer on paper.

Gomez said he enjoyed the opportunity to work on important research contributing to environmental sustainability. He said his role involves doing computational research, which calculates which compositions can significantly reduce COO.₂.

“Traditionally we have been shown that research comes from labs where you have to wear lab coats and work with hazardous chemicals,” Gomez said. “I was glad that every day I was always learning new things about research that I didn’t know could only be done through computer programs.”

“The first-hand experience I got was just the best I could ask for, as it allows me to explore my interests in the field of chemical engineering and to see how there are many ways to achieve life-saving research,” Gomez said. Said.