Scientists from around the world have tried out many materials unsuccessfully.
An assistant professor at the University of Central Florida has discovered an innovative way to trigger artificial photosynthesis to turn carbon dioxide into clean air by producing green energy.
According to Fernando Uribe-Romo, an assistant professor at the University of Central Florida, the finding of his team is “breakthrough”.
“Tailoring materials that will absorb a specific color of light is very difficult from the scientific point of view, but from the societal point of view we are contributing to the development of a technology that can help reduce greenhouse gasses,” said the assistant professor.
The researchers were able to achieve this feat by being able to trigger a chemical reaction in a synthetic material called metal-organic frameworks (MOF) that breaks down carbon dioxide into harmless organic materials.
They say that the chemical process is similar to nature’s photosynthesis where plants convert carbon dioxide and sunlight into food and produce oxygen as its byproduct but here instead of producing food, it produces solar fuel.
According to Prof. Fernando, scientists from around the world have been trying to find a way to trigger the chemical transformation through visible light.
According to him, the ultraviolet rays have energy particles that allow the reaction in materials such as titanium dioxide. The caveat is that UVs make up only about 4 percent of the light Earth receives from the sun.
The visible range – the violet to red wavelengths – represent the majority of the sun’s rays, but there are few materials that pick up these light colors to create the chemical reaction that transforms CO2 into fuel.
Even though scientists have tried out many materials that can absorb light, most of them are rare and highly expensive.
Uribe-Romo’s solution for this was to use easily available nontoxic metal titanium and added organic molecules that act as light-harvesting antennae to make the reaction work.
As a result, of which he designed the light harvesting antenna molecules, called N-alkyl-2-aminoterephthalates, that can absorb specific colors of light when incorporated in the MOF. In this case, he synchronized it for the color blue.
Professor and his team assembled a blue LED photoreactor to test the possibility of a hypothesis. Calculated volumes of carbon dioxide were gradually fed into the photoreactor — a glowing blue cylinder that looks like a tanning bed — to test whether the reaction can trigger artificial photosynthesis.
The glowing blue light came from strips of LED lights inside the chamber of the cylinder and mimic the sun’s blue wavelength, which was the indication of a successful reaction.
The reaction converted CO2 into two reduced forms of carbon, formate, and formamides (two kinds of solar fuel) and in the process cleaning the air.
“The goal is to continue to fine-tune the approach so we can create greater amounts of reduced carbon so it is more efficient,” Uribe-Romo said.
“The idea would be to set up stations that capture large amounts of CO2, like next to a power plant. The gas would be sucked into the station, go through the process and recycle the greenhouse gasses while producing energy that would be put back into the power plant,” he added.
Perhaps someday homeowners could purchase rooftop shingles made of the material, which would clean the air in their neighborhood while producing energy that could be used to power their homes.
“That would take new technology and infrastructure to happen,” Uribe-Romo said. “But it may be possible.”
Other members of the team who worked on the paper include UCF graduate student Matt Logan, who is pursuing a Ph.D. in chemistry, and undergraduate student Jeremy Adamson, who is majoring in biomedical sciences. Kenneth Hanson and his research group at Florida State University helped interpret the results of the experiments.